Question

A 21-foot ladder is leaning against a building. The base of the ladder is 7 feet from the base of the building.

Answer 1

X - the measure of the angle that the ladder makes with the ground

$\cos{x}= \frac{7}{21} \\ \\ \cos{x}= \frac{1}{3} \\ \\ x=\arccos{\frac{1}{3} } \approx 71^o$