Question

A 20 foot ladder is leaning up against the side of a house. The construction worker who put it there followed the directions on the ladder's specifications which said to make sure the ladder was at least 8 feet away from the base of the wall to ensure safety. Say we want to re-word the directions and specify the angle of elevation of the ladder instead. What could the directions say about the angle of elevation?

Answer 1

Keep the ladder at a 66 degree angle of elevation at most.

Explanation:

Hypotenuse is 20 feet

Adjacent side is 8 feet

We use inverse cosine to find the angle

arccos(8/20) = 66.4 deg