Question

A 15-ft ladder is propped against a vertical wall and makes a 72 ̊ angle with the ground. How far is the foot of the ladder from the base of the wall?

Answer 1

This is the application of trigonometry. The distance of the ladder from from the wall will be given by:
cos θ=(adjacent)/(hypotenuse)
θ=72°
adjacent=base (distance the ladder to base of the wall)= xft
hypotenuse=length of the ladder.
Therefore plugging our values in the formula we get:
cos 72=x/15
x=15 cos 72
x=4.635 ft
Hence we conclude that the foot of the ladder is 4.635 ft away from the base of the wall.