A 15-foot ladder is placed against a vertical wall of a building, with the bottom of the ladder standing on level ground 12 feet from the base of the building. How high up the wall does the ladder reach?

Answer 1

a^2 + b^2 = c^2

12^2 + b^2 = 15^2

144 + b^2 = 225

b^2 = 225 - 144

b = 9

Answer 2

A 19
​-foot
ladder is placed against a vertical wall of a​ building, with the bottom of the ladder standing on level ground 13

feet from the base of the building. How high up the wall does the ladder​ reach?