A cone of height H with a base of radius r is cut by a plane parallel to and h units above the base where h < H. Find the volume of the solid (frustum of a cone) below the plane.

Step-by-step explanation:

radius of cone = r

height of cone = H

Let the radius of upper cone is r' and the height of plane from the base is h. So, the height of upper cone = H - h

According to the diagram

    .... (1)

Volume of complete cone

Volume of upper cone

The volume of frustum of cone below the plane is

ΔV = V - V'

step-by-step explanation:

no, her answer is not correct.   we square the lengths of all sides and then determine whether the pythagorean theorem holds here:

9² + 15² = 306.   this is not equal to the square of the longest side ( that square being 395.   answer c is correct.

yes

step-by-step explanation:

yes