This is the concept of trigonometry, we are required to calculate the number of floors the building has given the information above;
# floors=[height of the building]/[height of each floor]
height of each floor=17 ft
let the height of the building be,h.
h is given by;
tan theta=opposite/adjacent
theta=80
opposite=h
adjacent=75 ft
thus
tan 80=h/75
h=75 tan 80
h=425.35 ft
thus the number of floors will be:
425.35/17
=25.020≈25 floors
