A 18​-foot ladder is placed against a vertical wall of a​ building, with the bottom of the ladder standing on level ground 7 feet from the base of the building. How high up the wall does the ladder​ reach?

Answer 1

Using the Pythagorean theorem, we can determine the height the ladder reaches on the wall.

Let x represent the height the ladder reaches on the wall.

According to the Pythagorean theorem: (height)^2 + (base)^2 = (hypotenuse)^2
x^2 + 7^2 = 18^2
x^2 + 49 = 324
x^2 = 275
x = √275
x ≈ 16.6 feet

Therefore, the ladder reaches approximately 16.6 feet up the wall.