The formula for the volume of a cone is (1/3)*area of the base * height.
The base is a circle, whose area is pi times radius^2. Here this is pi *
(r^2) = 3.14*(72 / 2 yd)^2 = 4069.44 yd^2. And so the volume is (1/3) *
4069.44 yd^2 * 24yd = 32,555.52 yd^3. I recommend that you find the
most common formulas of the geometrical figures and make a flashcard
that you can use at any moment.
1/5 is 2% or 0.2, therefor 2/5 is 4% or 0.4