Alejandro has three ladders that are 15, 10, and 12 feet in length. if he is trying to reach a window that is 8 feet from the ground

part a: how far does the bottom of the ladder need to be for the 15-foot ladder?

part b: how far does the bottom of the ladder need to be for the 10-foot ladder?

part c: how far does the bottom of the ladder need to be for the 12- foot ladder?