Question

If a ladder is to be placed 3 feet from the side of a house. If top of the ladder rests exactly on the edge of the house when it is placed at an angle of 72 degrees from the ground, how long is the ladder to the nearest foot?

Answer 1

7 feet long

Explanation:

This set up will give a right angle triangle where;

Length of the ladder is the hypotenuse = x

The distance of the ladder to the house is the adjacent = 3 feet

Angle of elevation theta = 72 degrees

Using the CAH in trigonometry identity;

cos theta = adjacent/hypotenuse

cos 72 = 3/hyp

hyp = 3/cos72

hyp = 3/0.4258

hyp = 7.05 feet

Hence the ladder is approximately 7 feet long