Mariah is setting up a volleyball net in her backyard. The poles to hold the net up are 10 feet high. Mariah needs to run a wire from the top of the pole to the ground to help make sure that when players hit the net, the pole doesn't fall down. This wire is called a guy wire. If Maria runs the wire from the top of the pole to a point on the ground 7 feet from the base of the pole, how long must the guy wire be ________.