A painter leans a 20-ft ladder against a building. The base of the ladder is 12 ft from the building. To the nearest foot, how high on the building does the ladder reach?

Answer 1

This forms a right angle triangle.

a^2 + b^2 = c^2

a^2 + 12^2 = 20^2

a^2 + 144 = 400

a^2 = 256

a = 16

Answer 2

a=16