Answer:
16
notice how a right triangle was formed, and the Pythagorean theorem could be used to solve this :
a^2 + b^2 = c^2
a^2 + 15^2 = 17^2
a^2 + 225 = 289
a^2 = 64
a= 8
multiply it by 2 to get the side of the base
8 * 2 = 16
The angle of depression is
tan^-1 3/7 = 23.2 deg
I believe 24 months because by then you will have accumulated $720 hope it helps
