Free. Exclusive. Just for you.
Four unique services that make learning easier, faster, and smarter - only on our website.

Surface area worksheet for prisms and pyramids with diagrams and dimensions.

Worksheet titled "Surface Area of Prisms and Pyramids" with nine problems, each showing a 3D geometric figure (prisms and pyramids) with labeled dimensions and a space to calculate the surface area.

Worksheet titled "Surface Area of Prisms and Pyramids" with nine problems, each showing a 3D geometric figure (prisms and pyramids) with labeled dimensions and a space to calculate the surface area.

PNG 612×792 19.2 KB Free · Personal Use
Quality Assured by Worksheets Library Team
Reviewed for educational accuracy and age-appropriateness
ID: #658728
Show Answer Key & Explanations Step-by-step solution for: Geometry Worksheets | Volume Worksheets
Let’s solve each problem one by one. We’ll find the surface area of each prism or pyramid by adding up the areas of all its faces.

---

Problem 1: Square Pyramid

Base = 2 cm × 2 cm → Area = 4 cm²
Each triangular face has base 2 cm and height 10 cm → Area of one triangle = (1/2) × 2 × 10 = 10 cm²
There are 4 triangles → Total lateral area = 4 × 10 = 40 cm²
Total Surface Area = Base + Lateral = 4 + 40 = 44 cm²

Check: All sides same, so yes — 4 identical triangles.

---

Problem 2: Triangular Prism

This is a right triangular prism with:
- Triangle base = 3 in, height = 6 in → Area of one triangle = (1/2) × 3 × 6 = 9 in² → Two triangles = 18 in²
- Rectangles:
- One rectangle: 3 in × 10 in = 30 in²
- One rectangle: 6 in × 10 in = 60 in²? Wait — no! The slant side isn’t given directly.

Wait — actually, looking at the diagram: it shows a right triangle with legs 3 in and 6 in? But that would make hypotenuse √(3²+6²)=√45≈6.7 in — but the diagram labels “2 in” on the left edge? Hmm.

Actually, re-examining: The figure shows a triangular prism where the triangular face has base 3 in, height 6 in, and the length of the prism is 10 in. Also, there’s a label “2 in” pointing to the vertical edge — maybe that’s the height of the rectangle? No — let me think again.

Actually, standard interpretation: For a triangular prism, you have two triangular bases and three rectangular sides.

Given:
- Triangle: base = 3 in, height = 6 in → area per triangle = 9 in² → total for both = 18 in²
- The three rectangles:
- Rectangle 1: 3 in × 10 in = 30 in²
- Rectangle 2: 6 in × 10 in = 60 in²? But wait — if the triangle is right-angled with legs 3 and 6, then the third side (hypotenuse) is √(3²+6²)=√45≈6.708 in → so third rectangle = 6.708 × 10 ≈ 67.08 in²

But the diagram also has a “2 in” labeled — perhaps that’s the height of the prism? No, the 10 in is clearly the length.

Wait — maybe the “2 in” is the height of the triangular face? But it says 6 in is the height. This is confusing.

Alternative approach: Maybe the triangle is not right-angled? But the diagram shows a right angle symbol inside the triangle — so yes, it is right-angled with legs 3 in and 6 in? But then why is there a “2 in” label?

Looking again: The “2 in” is labeled on the left vertical edge of the prism — which might be the height of the rectangular face corresponding to the leg of length 2? That doesn't match.

Perhaps I misread. Let me assume the triangle has base 3 in, height 6 in, and the prism length is 10 in. Then the three rectangular faces correspond to the three sides of the triangle times 10.

Sides of triangle: 3 in, 6 in, and hypotenuse = √(3² + 6²) = √45 = 3√5 ≈ 6.708 in

So rectangles:
- 3 × 10 = 30
- 6 × 10 = 60
- 6.708 × 10 ≈ 67.08

Total lateral area = 30 + 60 + 67.08 = 157.08
Plus two triangles: 2 × 9 = 18
Total SA = 157.08 + 18 = 175.08 in²

But the “2 in” label is still unexplained. Perhaps it's a typo or mislabel? Or maybe the triangle has base 3, height 2, and the 6 in is something else?

Wait — looking at the diagram again: The triangle has a base of 3 in, and a height of 6 in drawn from the apex perpendicular to the base — so area is (1/2)*3*6=9. The “2 in” is labeled on the side edge — perhaps that’s the width of the prism? But it says 10 in is the length.

I think there might be a mistake in my assumption. Let me try another way.

Perhaps the “2 in” is the height of the rectangular face that is not along the base or height? No.

Another idea: Maybe the triangle is isosceles? But the diagram shows a right angle.

Let me check online or standard problems — but since I can’t, I’ll go with the most logical: ignore the “2 in” as possibly a distractor or error, and use base 3, height 6, length 10.

But wait — in some diagrams, the “2 in” might be the apothem or something — no.

Perhaps the 6 in is the slant height? But it’s drawn as the height of the triangle.

I think I need to proceed with what makes sense. Let’s calculate with the right triangle having legs 3 and 6, hypotenuse √45, and length 10.

SA = 2*(area of triangle) + perimeter of triangle * length
Perimeter = 3 + 6 + √45 = 9 + 3√5 ≈ 9 + 6.708 = 15.708
Lateral area = 15.708 * 10 = 157.08
Base areas = 2 * 9 = 18
Total = 175.08 in²

Round to nearest hundredth: 175.08 in²

But let’s see if the “2 in” is meant to be used. Perhaps the triangle has base 3, and the two equal sides are 2 in? But then height wouldn’t be 6.

If base 3, and two sides 2, then height h = √(2² - (1.5)²) = √(4 - 2.25) = √1.75 ≈ 1.32, not 6.

So probably the “2 in” is a red herring or misprint. I’ll go with 175.08.

But let’s double-check with another method.

Perhaps the 6 in is not the height of the triangle but the length of the prism? No, the 10 in is labeled as the length.

I think I have to accept 175.08 for now.

Wait — looking at the diagram carefully: The "2 in" is labeled on the left vertical edge of the prism, which is likely the height of the rectangular face corresponding to the side of the triangle that is 2 in long. But in a right triangle with legs 3 and 6, the sides are 3,6,~6.7 — no 2.

Unless the triangle is not right-angled? But there is a right angle symbol.

Perhaps the 6 in is the hypotenuse? Let's try that.

Suppose the triangle has base 3 in, hypotenuse 6 in, then height h = √(6² - 3²) = √(36-9) = √27 = 3√3 ≈ 5.196 in

Then area of triangle = (1/2)*3*5.196 ≈ 7.794 in²

Sides: 3, 5.196, 6

Perimeter = 3 + 5.196 + 6 = 14.196

Lateral area = 14.196 * 10 = 141.96

Two bases = 2*7.794 = 15.588

Total SA = 141.96 + 15.588 = 157.548 ≈ 157.55 in²

And the "2 in" might be irrelevant or a mistake.

But the diagram shows the 6 in as the height from the apex to the base, not the hypotenuse.

I think the intended interpretation is that the triangle has base 3 in, height 6 in, and the prism length is 10 in, and the "2 in" is either a distractor or for another purpose.

Perhaps the "2 in" is the width of the top rectangle or something — but in a triangular prism, there are only three rectangles.

Another possibility: the "2 in" is the height of the prism, and the 10 in is something else — but the diagram shows 10 in as the length along the prism.

I recall that in some textbooks, for a triangular prism, they give the dimensions of the triangle and the length, and you calculate accordingly.

Let me look for a different approach. Perhaps the "2 in" is the apothem for the lateral faces, but that doesn't make sense.

I think I should move on and come back. Let's do other problems first.

---

Problem 3: Rectangular Prism

Dimensions: 10 mm × 4 mm × 3 mm

Surface area = 2(lw + lh + wh) = 2(10*4 + 10*3 + 4*3) = 2(40 + 30 + 12) = 2(82) = 164 mm²

Easy.

---

Problem 4: Pentagonal Pyramid

Base is a pentagon with side 4 yd, and the pyramid has a slant height of 12 yd, and the distance from center to side (apothem) is 10 yd? The diagram shows "10 yd" as the apothem of the base, and "12 yd" as the slant height of the triangular faces.

For a regular pyramid, surface area = base area + lateral area

Base area of regular pentagon = (1/2) * perimeter * apothem = (1/2) * (5*4) * 10 = (1/2)*20*10 = 100 yd²

Lateral area = (1/2) * perimeter * slant height = (1/2) * 20 * 12 = 120 yd²

Total SA = 100 + 120 = 220 yd²

Good.

---

Problem 5: Cube

Side = 2 mm

Surface area = 6 * s² = 6 * 4 = 24 mm²

Simple.

---

Problem 6: Trapezoidal Prism

The base is a trapezoid with parallel sides 4 yd and 11 yd, height of trapezoid is 3 yd (given as the height between the parallels), and the length of the prism is 6 yd.

First, area of trapezoid base = (1/2)*(b1+b2)*h = (1/2)*(4+11)*3 = (1/2)*15*3 = 22.5 yd²

Two bases = 45 yd²

Now, lateral area: the four rectangular faces.

The trapezoid has four sides: the two parallel sides (4 and 11), and the two non-parallel sides.

We need the lengths of the non-parallel sides. The diagram shows a right triangle with base (11-4)/2 = 3.5 yd? Wait, not necessarily symmetric.

The diagram shows a height of 3 yd for the trapezoid, and the difference in bases is 11-4=7 yd. If it's isosceles, then each overhang is 3.5 yd, so the non-parallel side = √(3.5² + 3²) = √(12.25 + 9) = √21.25 ≈ 4.61 yd

But the diagram doesn't specify if it's isosceles. However, in many such problems, it is assumed isosceles unless stated otherwise.

Also, the diagram has a "4 yd" labeled on the left non-parallel side? Let me see: it says "4 yd" on the left slanted side, and "3 yd" as the height, and "11 yd" bottom, "4 yd" top? No, top is 4 yd, bottom 11 yd, height 3 yd, and the left side is labeled "4 yd", which might be the length of the non-parallel side.

If the left non-parallel side is 4 yd, and the height is 3 yd, then the horizontal projection is √(4² - 3²) = √(16-9) = √7 ≈ 2.6458 yd

Similarly, the right non-parallel side: since the total difference in bases is 11-4=7 yd, and left overhang is 2.6458 yd, then right overhang is 7 - 2.6458 = 4.3542 yd, so right side length = √(3² + 4.3542²) = √(9 + 18.96) ≈ √27.96 ≈ 5.288 yd

This is messy, and probably not intended.

Perhaps the "4 yd" is the length of the non-parallel side, and we can use that.

Assume the trapezoid has sides: top 4 yd, bottom 11 yd, left leg 4 yd, right leg ?

With height 3 yd, the horizontal component for left leg is √(4² - 3²) = √7 ≈ 2.6458 yd

Then the right leg's horizontal component is 11 - 4 - 2.6458 = 4.3542 yd (since the top is shorter, the overhangs add up to 7 yd)

So right leg = √(3² + 4.3542²) = √(9 + 18.96) = √27.96 ≈ 5.288 yd

Then perimeter of trapezoid = 4 + 11 + 4 + 5.288 = 24.288 yd

Lateral area = perimeter * length of prism = 24.288 * 6 ≈ 145.728 yd²

Base areas = 2 * 22.5 = 45 yd²

Total SA = 145.728 + 45 = 190.728 ≈ 190.73 yd²

But this is complicated, and likely not what is intended.

Perhaps the "4 yd" is not the side length but something else. Looking at the diagram: it says "4 yd" on the left slanted side, and "3 yd" as the height of the trapezoid, and "11 yd" bottom, "4 yd" top? No, the top is labeled "4 yd"? In the diagram, the top base is not labeled, but the bottom is 11 yd, and the height is 3 yd, and the left side is 4 yd.

Another possibility: the "4 yd" is the length of the non-parallel side, and the trapezoid is right-angled on one side.

Suppose the left side is vertical? But it's slanted.

Perhaps it's a right trapezoid. Assume the left side is perpendicular, but the diagram shows it slanted.

I think for simplicity, many problems assume the non-parallel sides are equal, but here one is given as 4 yd.

Let's calculate with the given: left leg = 4 yd, height = 3 yd, so horizontal run = √(4^2 - 3^2) = √7 ≈ 2.6458 yd

Then the right leg's horizontal run = (11 - 4) - 2.6458 = 7 - 2.6458 = 4.3542 yd (since the top is 4 yd, bottom 11 yd, so the total overhang is 7 yd, split as 2.6458 on left, 4.3542 on right)

Then right leg = √(3^2 + 4.3542^2) = √(9 + 18.96) = √27.96 = 5.288 yd as before.

Perimeter = 4 (top) + 11 (bottom) + 4 (left) + 5.288 (right) = 24.288 yd

Lateral area = 24.288 * 6 = 145.728 yd²

Base area = (1/2)*(4+11)*3 = 22.5 yd² per base, so 45 yd² for two

Total SA = 145.728 + 45 = 190.728 ≈ 190.73 yd²

I'll go with that.

---

Problem 7: Hexagonal Prism

Base is a hexagon with side 2 cm, and the prism height is 3 cm, and the apothem is 10 cm? The diagram shows "10 cm" as the apothem of the hexagon, "2 cm" as the side, and "3 cm" as the height of the prism.

For a regular hexagon, area = (1/2) * perimeter * apothem = (1/2) * (6*2) * 10 = (1/2)*12*10 = 60 cm²

Two bases = 120 cm²

Lateral area = perimeter * height = 12 * 3 = 36 cm²

Total SA = 120 + 36 = 156 cm²

Note: In a regular hexagon, the apothem is related to the side by apothem = (s√3)/2, so for s=2, apothem = (2*1.732)/2 = 1.732 cm, but here it's given as 10 cm, which is inconsistent. So probably the "10 cm" is not the apothem but something else.

Looking at the diagram: it shows "10 cm" as the distance from center to vertex? Or to side? The label is on the line from center to the middle of a side, so it should be apothem.

But for a regular hexagon with side 2 cm, apothem is (√3/2)*2 = √3 ≈ 1.732 cm, not 10 cm. So likely, the "10 cm" is the radius (distance to vertex), not apothem.

In a regular hexagon, radius = side length, so if side is 2 cm, radius is 2 cm, not 10.

This is confusing. Perhaps the "10 cm" is the length of the diagonal or something.

Another possibility: the "10 cm" is the apothem, and the side is not 2 cm, but the diagram says "2 cm" for the side.

Perhaps the hexagon is not regular, but that would be unusual.

Let's read the diagram: it shows a hexagonal prism, with "2 cm" labeled on one side of the hexagon, "3 cm" as the height of the prism, and "10 cm" as the apothem (from center to midpoint of a side).

But mathematically, for a regular hexagon, apothem a = (s√3)/2, so s = 2a/√3 = 2*10/1.732 ≈ 11.547 cm, but the side is given as 2 cm, contradiction.

So probably, the "10 cm" is not the apothem but the radius (distance from center to vertex).

In a regular hexagon, radius r = s, so if r=10 cm, then s=10 cm, but the diagram says s=2 cm.

This is inconsistent.

Perhaps the "2 cm" is not the side length but something else. The diagram shows "2 cm" on the side of the hexagon, so likely side length.

Another idea: perhaps the "10 cm" is the length of the space diagonal or something, but that doesn't make sense for surface area.

I think there might be a mistake in the problem or my understanding.

Let's assume that the hexagon is regular with side 2 cm, and ignore the "10 cm" for now, or use it as apothem even though it's inconsistent.

If we use apothem = 10 cm, side = 2 cm, then area = (1/2)*perimeter*apothem = (1/2)*12*10 = 60 cm², as before.

Lateral area = perimeter * height = 12 * 3 = 36 cm²

Total 96 cm²? No, 60*2 = 120 for bases, plus 36 = 156 cm².

But geometrically impossible, but for the sake of the problem, perhaps that's what is intended.

Perhaps the "10 cm" is the height of the triangular faces or something, but for a prism, lateral faces are rectangles.

I think I have to go with 156 cm², assuming the apothem is 10 cm despite the inconsistency.

Or perhaps the "10 cm" is the diameter or something.

Another thought: in some diagrams, the "10 cm" might be the length of the diagonal across the hexagon, but for surface area, we need the base area.

Let's calculate the area of a regular hexagon with side 2 cm: it is (3√3/2) * s^2 = (3*1.732/2)*4 = (5.196/2)*4 = 2.598*4 = 10.392 cm² per base.

Then two bases = 20.784 cm²

Lateral area = 6 * (2 * 3) = 6*6 = 36 cm² (since each rectangle is 2 cm by 3 cm)

Total SA = 20.784 + 36 = 56.784 ≈ 56.78 cm²

And ignore the "10 cm" as perhaps a distractor or for another purpose.

But the diagram has "10 cm" labeled, so likely it's important.

Perhaps the "10 cm" is the apothem, and the side is not 2 cm, but the "2 cm" is the apothem or something.

Let's swap: suppose "2 cm" is the apothem, "10 cm" is the side.

Then area = (1/2)*perimeter*apothem = (1/2)*(6*10)*2 = (1/2)*60*2 = 60 cm² per base? No, for two bases 120 cm².

Lateral area = perimeter * height = 60 * 3 = 180 cm²

Total 300 cm², but then the "2 cm" is apothem, "10 cm" is side, but the diagram shows "2 cm" on the side, so unlikely.

I think the best bet is to use the given numbers as is: side 2 cm, apothem 10 cm, height 3 cm, so base area = (1/2)*12*10 = 60 cm², lateral 36 cm², total 156 cm².

So 156 cm²

---

Problem 8: Triangular Pyramid (Tetrahedron?)

The diagram shows a triangular pyramid with base triangle having sides 13 ft, 7 ft, and the height from apex to base is 12 ft, but also there is a "13 ft" on the edge.

It looks like the base is a triangle with sides 13 ft, 7 ft, and the third side is not given, but there is a height of 12 ft from the apex to the base, and also a "13 ft" on the lateral edge.

This is ambiguous.

Perhaps it's a pyramid with a triangular base, and the base is a right triangle or something.

The diagram shows a base triangle with sides 13 ft and 7 ft, and the height of the pyramid is 12 ft, but for surface area, we need the areas of the four triangular faces.

Typically, for a pyramid, if it's regular, but here it's not specified.

Perhaps the "12 ft" is the slant height for the faces.

Looking at the diagram: it shows a pyramid with a triangular base, and from the apex, there is a perpendicular to the base of length 12 ft, and the base has sides 13 ft and 7 ft, and the lateral edges are 13 ft.

This is complicated.

Perhaps the base is a triangle with base 7 ft, and the other two sides are 13 ft each, making it isosceles, and the height of the pyramid is 12 ft.

Then, first, area of base: for isosceles triangle with sides 13,13,7, height h = √(13^2 - (3.5)^2) = √(169 - 12.25) = √156.75 ≈ 12.52 ft

Area = (1/2)*7*12.52 = 43.82 ft²

Then for the lateral faces: there are three triangular faces.

The two identical ones: each has base 13 ft (the equal sides of the base), and the slant height from apex to those bases.

The distance from the apex to a base vertex is the lateral edge, which is given as 13 ft? The diagram shows "13 ft" on the lateral edge.

So for a lateral face that is a triangle with sides 13 ft (lateral edge), 13 ft (base edge), and the other lateral edge.

This is messy.

Perhaps the "12 ft" is the slant height for the faces.

Another common type: if the pyramid has a triangular base, and the apex is directly above the centroid, but here it's not specified.

Perhaps for this problem, the "12 ft" is the height of the triangular faces.

Let's assume that the base is a triangle with sides 13 ft, 7 ft, and the third side is say c, but not given.

Perhaps the base is right-angled. Suppose the base is a right triangle with legs 7 ft and x, hypotenuse 13 ft, then x = √(13^2 - 7^2) = √(169-49) = √120 = 2√30 ≈ 10.954 ft

Then area of base = (1/2)*7*10.954 = 38.339 ft²

Then the lateral faces: each is a triangle with base as the side of the base, and height from apex.

But we need the slant heights.

The diagram shows "12 ft" as the height from apex to the base plane, so for each lateral face, the slant height can be found using Pythagoras with the distance from the foot of the perpendicular to the side.

This is very complicated for a homework problem.

Perhaps the "12 ft" is the slant height for all faces, but that would be unusual.

Another idea: perhaps the pyramid is such that the lateral faces are triangles with base 7 ft, 13 ft, etc., and height 12 ft.

For example, if each lateral face has height 12 ft from the apex to the base edge.

Then for the face with base 7 ft, area = (1/2)*7*12 = 42 ft²

For the face with base 13 ft, area = (1/2)*13*12 = 78 ft²

But there are three lateral faces, and the base is also a triangle.

The base has sides 7 ft, 13 ft, and the third side. If we assume the third side is also given or can be found.

From the diagram, it seems there are three lateral edges of 13 ft, and the base has sides 7 ft and 13 ft, so perhaps the base is isosceles with sides 13,13,7, as I thought earlier.

Let me try that.

Base: isosceles triangle with sides 13 ft, 13 ft, 7 ft.

Height of base triangle h_b = √(13^2 - (3.5)^2) = √(169 - 12.25) = √156.75 = √(627/4) = (√627)/2, but numerically 12.52 ft as before.

Area of base = (1/2)*7*12.52 = 43.82 ft²

Now, the apex is directly above the centroid or orthocenter? For surface area, we need the areas of the three lateral faces.

Each lateral face is a triangle with two sides 13 ft (lateral edges) and base as the side of the base triangle.

So for the face corresponding to the base side of 7 ft: it is an isosceles triangle with sides 13,13,7.

Its height h_l = √(13^2 - (3.5)^2) = same as above, 12.52 ft

Area = (1/2)*7*12.52 = 43.82 ft²

For the faces corresponding to the 13 ft sides of the base: each is a triangle with sides 13 ft (lateral edge), 13 ft (base edge), and the other lateral edge 13 ft? No, the lateral edges are all 13 ft, so for a lateral face with base 13 ft, the two other sides are 13 ft each, so it is equilateral!

Is that possible? If the base has a side of 13 ft, and the two lateral edges to its endpoints are both 13 ft, then yes, the lateral face is equilateral with side 13 ft.

So for each of the two faces with base 13 ft, area = (√3/4) * s^2 = (1.732/4)*169 = 0.433*169 ≈ 73.177 ft²

And for the face with base 7 ft, as above, area = 43.82 ft²

Then total lateral area = 43.82 + 73.177 + 73.177 = 190.174 ft²

Base area = 43.82 ft²

Total SA = 190.174 + 43.82 = 233.994 ≈ 234.00 ft²

But the diagram shows "12 ft" as the height from apex to base, which we haven't used. In this calculation, we didn't use the 12 ft; we used the lateral edges as 13 ft.

Perhaps the "12 ft" is the height of the pyramid, not the lateral edge.

Let's try that.

Assume the base is a triangle with sides 13 ft, 7 ft, and say c, and the apex is 12 ft above the base plane.

But we need more information.

Perhaps the base is right-angled with legs 7 ft and 12 ft, but 12 ft is the height of the pyramid.

I think for the sake of time, and since the diagram shows "12 ft" as the height from apex to base, and "13 ft" on the lateral edge, let's assume the base is a right triangle with legs 5 ft and 12 ft, but 5-12-13 is a right triangle.

Oh! Perhaps the base is a 5-12-13 right triangle, but the diagram shows 7 ft and 13 ft, not 5 and 12.

7 and 13 don't form a right triangle with integer sides.

7^2 + 12^2 = 49 + 144 = 193, not 169.

13^2 = 169, 7^2 = 49, 169-49=120, not square.

Perhaps the "7 ft" is not a side but something else.

Another idea: perhaps the "7 ft" is the base of the triangle, and "13 ft" is the equal sides, and "12 ft" is the height of the pyramid.

Then, as before, base area = (1/2)*7*√(13^2 - 3.5^2) = (1/2)*7*√(169-12.25) = (1/2)*7*√156.75

√156.75 = √(627/4) = (√627)/2, √625=25, √627≈25.04, so 12.52, as before.

Area base = 43.82 ft²

Now, the apex is 12 ft above the base. To find the area of a lateral face, we need the slant height, which is the distance from the apex to the base edge.

For example, for the face with base 7 ft, the slant height can be found if we know the distance from the foot of the perpendicular to the base edge.

In an isosceles triangle, the foot of the perpendicular from apex to base is at the midpoint of the base, so for the base side of 7 ft, the distance from the foot to the side is 0 if it's on the side, but for the lateral face, the slant height is the distance from apex to the base edge along the face.

For the lateral face that is a triangle with base 7 ft, and the two other sides are the lateral edges.

The length of the lateral edge can be found from the height of the pyramid and the distance from the foot to the vertex.

In the base, for the isosceles triangle with sides 13,13,7, the height is 12.52 ft, and the centroid or orthocenter is at 2/3 the height from the apex, but for the foot of the perpendicular from the pyramid apex, if it's above the centroid, then the distance from foot to a vertex can be calculated.

This is too advanced for this level.

Perhaps for this problem, the "12 ft" is the slant height for the faces.

Let's assume that each lateral face has a height of 12 ft from the apex to the base edge.

Then for the face with base 7 ft, area = (1/2)*7*12 = 42 ft²

For the face with base 13 ft, area = (1/2)*13*12 = 78 ft²

But there are two faces with base 13 ft? In the base triangle, if it's isosceles with sides 13,13,7, then there are two faces with base 13 ft, and one with base 7 ft.

So lateral area = 2*78 + 42 = 156 + 42 = 198 ft²

Base area = 43.82 ft²

Total SA = 198 + 43.82 = 241.82 ft²

But we have the "12 ft" as the height of the pyramid, not the slant height.

Perhaps the "12 ft" is the slant height.

In many problems, they give the slant height for pyramids.

So let's assume that the slant height for all lateral faces is 12 ft.

Then for each lateral face, area = (1/2) * base * slant height

So for the three faces:
- Face 1: base 7 ft, area = (1/2)*7*12 = 42 ft²
- Face 2: base 13 ft, area = (1/2)*13*12 = 78 ft²
- Face 3: base 13 ft, area = 78 ft²

Total lateral area = 42 + 78 + 78 = 198 ft²

Base area = as before, for isosceles triangle with sides 13,13,7, area = (1/2)*7*√(13^2 - 3.5^2) = (1/2)*7*√(169-12.25) = (1/2)*7*√156.75

Calculate √156.75: 12.52^2 = 156.7504, yes, so (1/2)*7*12.52 = 3.5*12.52 = 43.82 ft²

Total SA = 198 + 43.82 = 241.82 ft²

Round to nearest hundredth: 241.82 ft²

And the "12 ft" is the slant height, not the height of the pyramid.

In the diagram, it's drawn as the height from apex to base, but perhaps it's meant to be the slant height.

I think this is reasonable.

So 241.82 ft²

---

Problem 9: Hexagonal Pyramid

Base is a hexagon with side 5 in, and the slant height is 13 in, and the apothem is 11 in? The diagram shows "5 in" for the side, "13 in" for the slant height of the triangular faces, and "11 in" for the apothem of the base.

For a regular hexagonal pyramid, surface area = base area + lateral area

Base area = (1/2) * perimeter * apothem = (1/2) * (6*5) * 11 = (1/2)*30*11 = 165 in²

Lateral area = (1/2) * perimeter * slant height = (1/2) * 30 * 13 = 195 in²

Total SA = 165 + 195 = 360 in²

Note: In a regular hexagon, apothem a = (s√3)/2 = (5*1.732)/2 = 4.33 in, but here it's given as 11 in, so again inconsistent, but for the problem, we use the given numbers.

So 360 in²

---

Now back to Problem 2.

After re-thinking, perhaps the "2 in" is the height of the rectangular face corresponding to the side of length 2 in, but in the triangle, if it's right-angled with legs 3 in and 6 in, then the sides are 3,6,√45, no 2.

Perhaps the triangle has base 3 in, and the two other sides are 2 in and 6 in, but then it's not right-angled.

Assume the triangle has sides 2 in, 3 in, 6 in, but 2+3<6, impossible.

2+3=5<6, so not a triangle.

So must be that the "2 in" is not a side of the triangle.

Perhaps the "2 in" is the width of the prism, but the 10 in is the length.

I think the only logical choice is to assume the triangle has base 3 in, height 6 in, so area 9 in², and the three rectangular faces have widths 3 in, 6 in, and the hypotenuse √(3^2+6^2)=√45=3√5≈6.708 in, and length 10 in.

So lateral area = 10*(3 + 6 + 6.708) = 10*15.708 = 157.08 in²

Base areas = 2*9 = 18 in²

Total 175.08 in²

And the "2 in" might be a mistake or for another purpose.

So I'll go with 175.08 in²

For Problem 7, I'll use the given apothem 10 cm, side 2 cm, so base area = (1/2)*12*10 = 60 cm², lateral 12*3=36 cm², total 156 cm².

For Problem 8, with slant height 12 ft, base sides 7,13,13, lateral area 198 ft², base 43.82 ft², total 241.82 ft².

Now let's list all answers.

1) 44 cm²

2) 175.08 in²

3) 164 mm²

4) 220 yd²

5) 24 mm²

6) 190.73 yd²

7) 156 cm²

8) 241.82 ft²

9) 360 in²

For Problem 6, I had 190.73, but let's confirm the calculation.

Trapezoid: parallel sides 4 yd and 11 yd, height 3 yd, so area = (1/2)*(4+11)*3 = 22.5 yd² per base, so 45 yd² for two.

Non-parallel sides: left side 4 yd (given), with height 3 yd, so horizontal component = √(4^2 - 3^2) = √7 ≈ 2.6458 yd

Then the right side's horizontal component = (11 - 4) - 2.6458 = 7 - 2.6458 = 4.3542 yd (since the top is 4 yd, bottom 11 yd, so the overhang on left is 2.6458 yd, on right is 4.3542 yd)

Then right side length = √(3^2 + 4.3542^2) = √(9 + 18.96) = √27.96 = 5.288 yd (since 5.288^2 = 27.96)

Perimeter = 4 (top) + 11 (bottom) + 4 (left) + 5.288 (right) = 24.288 yd

Lateral area = 24.288 * 6 = 145.728 yd²

Total SA = 145.728 + 45 = 190.728 ≈ 190.73 yd²

Yes.

For Problem 8, base area: isosceles triangle with sides 13,13,7.

Height = √(13^2 - (7/2)^2) = √(169 - 12.25) = √156.75 = √(627/4) = (√627)/2

√627: 25^2=625, so √627 = √(625+2) ≈ 25 + 2/(2*25) = 25.04, so 12.52

Area = (1/2)*7*12.52 = 43.82 ft²

Lateral faces: two with base 13 ft, slant height 12 ft, area each (1/2)*13*12 = 78 ft²

One with base 7 ft, slant height 12 ft, area (1/2)*7*12 = 42 ft²

Total lateral = 78+78+42 = 198 ft²

Total SA = 198 + 43.82 = 241.82 ft²

Yes.

So final answers:

1) 44.00 cm²

2) 175.08 in²

3) 164.00 mm²

4) 220.00 yd²

5) 24.00 mm²

6) 190.73 yd²

7) 156.00 cm²

8) 241.82 ft²

9) 360.00 in²

For Problem 1, I have 44, which is exact.

For others, rounded to nearest hundredth as instructed.

Now to box the answers.

Final Answer:
1) 44.00 cm²
2) 175.08 in²
3) 164.00 mm²
4) 220.00 yd²
5) 24.00 mm²
6) 190.73 yd²
7) 156.00 cm²
8) 241.82 ft²
9) 360.00 in²
Parent Tip: Review the logic above to help your child master the concept of worksheet on surface area and volume.
Print Download

How to use

Click Print to open a print-ready version directly in your browser, or use Download to save the file to your device. The ⭐ Answer button generates an AI answer key instantly - useful for teachers who need a quick reference. Need a different version? Our AI Worksheet Generator lets you create a custom worksheet on any topic in seconds.

(view all worksheet on surface area and volume)

Volume and Surface Area
Volume and Surface Area of Triangular Prisms (A)
Surface Area and Volume Worksheet for 9th - 10th Grade | Lesson Planet
Volume And Surface Area Worksheets Grade 7 [PDFs] Brighterly
Free worksheets for the volume and surface area of cubes ...
CBSE Class 9 Mathematics Surface Area And Volume Worksheet Set A
volume and Surface Area of Cubes worksheets
Volume &amp; Surface Area
Volume and Surface Area of Rectangular Prisms with Decimal Numbers (A)
Surface Area and Volume Worksheet for 6th - 7th Grade | Lesson Planet