The latter is leaning against the building so that the distance from the ground to the top of the ladder is 9 feet less than the length of the ladder finally put the ladder in the distance from the bottom of the ladder to the building 15 feet. Find length of the ladder.
The pythagorean theorem states that the sum of two legs to the 2nd power is equivalent to the hypotenuse to the 2nd power () . Do note that the pythagorean theorem only works with right triangles.