I don’t know the answer to this but I have an app called Socratic, it helps out with problems like this, download it and take a picture of what you are looking for, and it will give you the answers. I hope this helps..
Ladder makes a right triangle with the wall and ground. The hypotenuse = length of the ladder = 10 ft Let the height be h By Pythagorean theorem 10^2 = 3^2 + h^2 h^2 = 10^2 - 3^2 = 100 - 9 = 91 h = sqrt( 91) = 9.54 ft
