+129899 The area of the base is given by
(1/2) AB * AC sin (90) = AB * AC / 2 = x * x / 2 = x^2 / 2
The height is AD = 2AB = 2x
So.......using the formula
72 = (1/3) base area * height .... subbing the above, we have
72 = (1/3) [x^2/2] * [2x]
72 = (1/3) [ x^3] multiply both sides by 3
216 = x^3 take the cube root of both sides
6 (cm) = x
