Question

A 20 ft ladder leans against a building making an angle of 72 degrees with the ground. find the nearest foot the distnace between the base of the ladder and building.

Answer 1

Let:

$$L = 20 ft, \alpha = 72{}^\circ;$$ $$S = ?$$

From a rectangular triangle:

$$S = L * \cos \alpha;$$ $$S = 20 * \cos 72{}^\circ = 20 * 0.309 = 6.18 ft;$$

Answer: 6.18 ft.