The bottom of the ladder is 8 feet from the wall and the top of the ladder against the wall is 15 feet up, how tall is the ladder

Question

A ladder leaning against a wall. Thr bottom of the ladder is 8 feet from the wall. The top of the ladder against the wall is 15 feet up. How long is the ladder?

Answer 1

The ladder and wall are part of a right-angled triangle with base 8' and height 15'. The ladder forms a hypotenuse therefore its length by Pythagoras is √(15^2+8^2)=√289=17'.