Question

A cone has a diameter of 6 centimeters and a height that is 3 times the diameter. Using 3.14 for pi, which of the following can be used to calculate the volume of the cone?

one over three(3.14)(3cm)2(18cm)
one over three(3.14)(6cm)2(18cm)
one over three(3.14)(18cm)2(3cm)
one over three(3.14)(18cm)2(6cm)

Answer 1

Answer is first option.

Explanation:

V = 1/3* 3^2*3,14*18

Answer 2

The volume of the cone is calculated by the formula:

V = B*H/3
r=D/2 = 6/3 = 2
where B is surface area of basis and H is height.

B is circle which fomula for surface is:
B = r^2 * pi = 3^2*3,14 = 9*3,14 = 28.26

from condition of height we write:
H = 3*D = 3*6 = 18

now volume is:

If we express all of that in equation of volume we get:

V = 1/3* 3^2*3,14*18

Answer is first option.