Cylinders: volume problems, including a missing radius or height

Answer Key - Grade 8 Math Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. 1.

   Ari's candle is a cylinder with a radius of 2 cm and a height of 9 cm. The figure shows one circle layer. What is its volume in cubic cm?

   113.04
2. 2.

   Bo's jar is a cylinder with a radius of 4 cm and a height of 7 cm. The figure shows one circle layer. What is its volume in cubic cm?

   351.68
3. 3.

   Jun's can is a cylinder with a radius of 3 cm and a height of 11 cm. The figure shows one circle layer. What is its volume in cubic cm?

   310.86
4. 4.

   Kira's mug is a cylinder with a radius of 5 cm and a height of 7 cm. The figure shows one circle layer. What is its volume in cubic cm?

   549.5
5. 5.

   “Sketch, not to scale:” Luz's can is a cylinder with a radius of 4 cm. It holds 653.12 cubic cm, and one circle layer has an area of 50.24 square cm. How tall is it, in cm?

   13
6. 6.

   Milo's toy drum is a cylinder with a radius of 7 cm. It holds 923.16 cubic cm, and one circle layer has an area of 153.86 square cm. How tall is it, in cm?

   6
7. 7.

   Noah's pot is a cylinder with a radius of 5 cm. It holds 706.5 cubic cm, and one circle layer has an area of 78.5 square cm. How tall is it, in cm?

   9

8. Read this first

   Sketch, not to scale

   The candle cut into ? layers, each 1 cm thick. One layer is a circle of area 12.56 square cm; the layers add up to 150.72 cubic cm.

9. 8.

   Ren's candle is a cylinder with a radius of 2 cm. It holds 150.72 cubic cm, and one circle layer has an area of 12.56 square cm. How tall is it, in cm?

   12
10. 9.

    Zee's toy drum is a cylinder. One circle layer has an area of 314 square cm, so 3.14 × r × r = 314. What is the radius r, in cm?

    10
11. 10.

    Bo's round tin is a cylinder. One circle layer has an area of 254.34 square cm, so 3.14 × r × r = 254.34. What is the radius r, in cm?

    9