Question

What is the exact volume of the cone? (height is 9 cm, the radius is 15 cm)

A)90 n cm 3
B)675 n cm 3
C)225 n cm 3
D)405 n cm 3

What is the approximate volume of the cone? use 3.14 for n. (height 9 cm, the radius is 10 cm)
A)94 cm 3
B)565 cm 3
C)942 cm 3
D)2826 cm 3

What is the approximate volume of a cone with a diameter of 10 meters and height of 5 meters? use 3.14 for n.
A)130.8 m 3
B)314 m 3
C)392.5 m 3
D)1570 m 3

Answer 1

D is the answerr to the first one.

Answer 2

1: Exact volume of cone = r^2 * h/ 3 = 15^2 * 9 / 3 = 225 * 9= 2025/3 = 675

2: Approximate volume of cone: pi* r^2 * h / 3 = 3.14 * 10^2 * 9/3 = 3.14 * 100* 9/3 = 3.14 x 900 / 3 = 2826/3 = 942 cm^3

3: Asks for the same as problem above, but we have to divide the diameter by 2 to get the radius first 10/2=5 now we can solve. : 3.14 * 5^2 * 5/3 = 3.14 * 25 * 5/ 3 = 3.14 * 125 / 3 = 392.5/ 3 = 130.8 m^3

The exact volume does not use pi: so that is why the first one is 675
The Approximate used pi or 3.14.