Question

How far away from a wall you must place in 18' ladder in order to reach a roof that is 12' high

Answer 1

Let's make a diagram

To find x, we have to use Pythagorean's Theorem

$\begin{gathered} 18^2=x^2+12^2 \\ x=\sqrt[]{324-144} \\ x=\sqrt[]{180} \\ x\approx13.4 \end{gathered}$

Hence, the ladder is 13.4' away from the wall.