Surface Area of Prisms and Cylinders Worksheets - 15 Worksheets Library - Free Printable

Let’s solve each problem step by step.

We are finding the surface area of cylinders.
The formula given is:
SA = 2πr(r + h)
Where:
- r = radius of the base
- h = height of the cylinder
- π ≈ 3.14 (we’ll use this for all calculations)

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Problem 1:

Radius = 8 mm, Height = 8 mm
SA = 2 × 3.14 × 8 × (8 + 8)
= 2 × 3.14 × 8 × 16
First: 8 × 16 = 128
Then: 2 × 3.14 = 6.28
Then: 6.28 × 128 = let’s compute:
6 × 128 = 768
0.28 × 128 = 35.84
Total = 768 + 35.84 = 803.84 mm²

✔ Final Answer for #1: 803.84

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Problem 2:

Radius = 8 cm, Height = 12 cm
SA = 2 × 3.14 × 8 × (8 + 12)
= 2 × 3.14 × 8 × 20
First: 8 × 20 = 160
Then: 2 × 3.14 = 6.28
Then: 6.28 × 160 =
6 × 160 = 960
0.28 × 160 = 44.8
Total = 960 + 44.8 = 1004.8 cm²

✔ Final Answer for #2: 1004.8

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Problem 3:

Radius = 8 yd, Height = 12 yd → Same as #2 but in yards
So same calculation:
SA = 2 × 3.14 × 8 × (8 + 12) = 1004.8 yd²

✔ Final Answer for #3: 1004.8

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Problem 4:

Radius = 4 mm, Height = 6 mm
SA = 2 × 3.14 × 4 × (4 + 6)
= 2 × 3.14 × 4 × 10
First: 4 × 10 = 40
Then: 2 × 3.14 = 6.28
Then: 6.28 × 40 = 251.2 mm²

✔ Final Answer for #4: 251.2

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Problem 5:

Radius = 4 in, Height = 4 in
SA = 2 × 3.14 × 4 × (4 + 4)
= 2 × 3.14 × 4 × 8
First: 4 × 8 = 32
Then: 2 × 3.14 = 6.28
Then: 6.28 × 32 =
6 × 32 = 192
0.28 × 32 = 8.96
Total = 192 + 8.96 = 200.96 in²

✔ Final Answer for #5: 200.96

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Problem 6:

Radius = 4 ft, Height = 6 ft
SA = 2 × 3.14 × 4 × (4 + 6)
= 2 × 3.14 × 4 × 10
Same as #4 → 251.2 ft²

✔ Final Answer for #6: 251.2

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Problem 7:

Radius = 3 cm, Height = 4 cm
SA = 2 × 3.14 × 3 × (3 + 4)
= 2 × 3.14 × 3 × 7
First: 3 × 7 = 21
Then: 2 × 3.14 = 6.28
Then: 6.28 × 21 =
6 × 21 = 126
0.28 × 21 = 5.88
Total = 126 + 5.88 = 131.88 cm²

✔ Final Answer for #7: 131.88

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Problem 8:

Radius = 8 yd, Height = 12 yd → Same as #2 and #3
SA = 2 × 3.14 × 8 × (8 + 12) = 1004.8 yd²

✔ Final Answer for #8: 1004.8

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Problem 9:

Radius = 3 ft, Height = 4 ft → Same as #7 but in feet
SA = 2 × 3.14 × 3 × (3 + 4) = 131.88 ft²

✔ Final Answer for #9: 131.88

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Final Answer:
1) 803.84
2) 1004.8
3) 1004.8
4) 251.2
5) 200.96
6) 251.2
7) 131.88
8) 1004.8
9) 131.88