an 18-foot ladder leans against the wall of a building. the base of the ladder is 9 feet from the bulding on level ground.how many feet up the wall,to the nearest tenth of a foot,is the ladder?

Answer 1

The ladder forms the hypotenuse of a right triangle. Solve for a

a^2 + b^2 = c^2
a^2 + 9^2 = 18^2
a^2 + 81 = 324
a^2 = 243
a = 15.589 = 15.6 feet