A guy wire is used to support flagpoles in windy areas. These wires are anchored in the ground to provide constant stability. You need to replace the guy wire on a pole that is 20 feet tall.. The anchor point for this flagpole s 15 feet away from the base of the pole. a. How long is the wire you need to purchase to replace the old wire? . You are also helping a friend determine the length of a guy wire for a 10-foot flagpole. The wire needs to be anchored 6 feet from the base of the pole. You can purchase guy wires in whole foot lengths only. Using your knowledge of perfect squares, estimate the length of wire you would need to complete the project. How much wire