Calculate the volume of a cylinder with radius 3 cm and height 5 cm.

Calculate the volume of a cylinder with radius 3 cm and height 5 cm.

• A. 9π cm^3
• B. 15π cm^3
• C. 90π cm^3
• D. 45π cm^3

Answer: (D)

Volume inside a cylinder is found by multiplying the area of the circular base by its height. The base circle has radius 3 cm, so its area is πr^2 = π(3)^2 = 9π cm^2. Multiply that by the height, 5 cm, to get 9π × 5 = 45π cm^3. So the cylinder’s volume is 45π cubic centimeters. That matches the value 45π cm^3. The other numbers come from either forgetting to multiply by the height or forgetting to square the radius.

Volume inside a cylinder is found by multiplying the area of the circular base by its height. The base circle has radius 3 cm, so its area is πr^2 = π(3)^2 = 9π cm^2. Multiply that by the height, 5 cm, to get 9π × 5 = 45π cm^3. So the cylinder’s volume is 45π cubic centimeters. That matches the value 45π cm^3. The other numbers come from either forgetting to multiply by the height or forgetting to square the radius.