please help i need the answer to this problem

Question

A 20-foot ladder is placed against a building. If the top of the ladder will lean against the building 15-feet high, how far away from the base of the building is the bottom of the ladder located? Include a sketch that shows all known information and clearly shows what you need to find. Show all work and give the exact answer.

Answer 1

Draw a right triangle with horizontal leg of length x, vertical leg of length 15 and hypotenuse of length 20.

By the Pythagorean Theorem, x² + 225 = 400

So, x² = 175

x = √175 = √25√7 = 5√7 ft