Perimeter of Polygons Worksheets - Math Monks - Free Printable

Let’s solve each problem step by step. We’re finding the perimeter — that means adding up all the side lengths of each shape.

Some shapes have marks (like little lines or ticks) on their sides. Those marks mean those sides are equal in length. So if two sides have the same mark, they’re the same size!

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Problem 1: Rectangle

We see:
- Bottom = 16.4 ft
- Right side = 8.2 ft
- The top and bottom have the same tick → so top = 16.4 ft
- Left and right have double ticks → so left = 8.2 ft

Perimeter = 16.4 + 8.2 + 16.4 + 8.2
= (16.4 + 16.4) + (8.2 + 8.2)
= 32.8 + 16.4
= 49.2 ft

✔ Check: 16.4 × 2 = 32.8; 8.2 × 2 = 16.4; total = 49.2 ✔️

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Problem 2: Rhombus (all sides equal)

All four sides have the same single tick → all sides = 1.9 m

Perimeter = 1.9 + 1.9 + 1.9 + 1.9
= 1.9 × 4
= 7.6 m

✔ Check: 1.9 × 4 = 7.6 ✔️

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Problem 3: Trapezoid with some equal sides

Given:
- Top = 33.8 m
- Bottom = 45.7 m
- Right side = 13.5 m
- Left side has same tick as right side → so left = 13.5 m

Perimeter = 33.8 + 45.7 + 13.5 + 13.5
First add 13.5 + 13.5 = 27
Then 33.8 + 45.7 = 79.5
Then 79.5 + 27 = 106.5 m

✔ Check: 33.8 + 45.7 = 79.5; 13.5×2=27; 79.5+27=106.5 ✔️

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Problem 4: Regular octagon (8 equal sides)

One side = 4.8 in → all 8 sides are equal

Perimeter = 4.8 × 8
Let’s compute:
4 × 8 = 32
0.8 × 8 = 6.4
Total = 32 + 6.4 = 38.4 in

✔ Check: 4.8 × 8 = 38.4 ✔️

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Problem 5: Parallelogram

Opposite sides are equal:
- Top = 6 cm → bottom = 6 cm
- Right = 4.3 cm → left = 4.3 cm

Perimeter = 6 + 4.3 + 6 + 4.3
= (6 + 6) + (4.3 + 4.3)
= 12 + 8.6
= 20.6 cm

✔ Check: 6×2=12; 4.3×2=8.6; 12+8.6=20.6 ✔️

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Problem 6: Regular pentagon (5 equal sides)

One side = 16.6 ft → all 5 sides equal

Perimeter = 16.6 × 5
Compute:
16 × 5 = 80
0.6 × 5 = 3
Total = 80 + 3 = 83 ft

✔ Check: 16.6 × 5 = 83 ✔️

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Problem 7: Square? Wait — it's a rectangle with all sides marked equally?

Wait — look at the marks:
- All four sides have the SAME single tick → so ALL sides are equal → it’s a square!
Top = 8.8 km → so all sides = 8.8 km

Perimeter = 8.8 × 4
8 × 4 = 32
0.8 × 4 = 3.2
Total = 32 + 3.2 = 35.2 km

✔ Check: 8.8 × 4 = 35.2 ✔️

*(Note: Even though it looks like a rectangle, the tick marks tell us all sides are equal — so treat as square.)*

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Problem 8: Kite or diamond shape — let’s check the marks

It’s divided into triangles, but we care about outer perimeter.

Looking at the outer edges:
- Two sides have single tick → each = 10.8 in
- Two sides have double tick → each = 4.2 in

So perimeter = 10.8 + 10.8 + 4.2 + 4.2
= (10.8 × 2) + (4.2 × 2)
= 21.6 + 8.4
= 30.0 in

✔ Check: 10.8×2=21.6; 4.2×2=8.4; 21.6+8.4=30 ✔️

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Final Answer:

1. 49.2 ft
2. 7.6 m
3. 106.5 m
4. 38.4 in
5. 20.6 cm
6. 83 ft
7. 35.2 km
8. 30.0 in