Keisha, Dwayne, and Lonzell are planning for a new bridge to replace the old bridge. The new bridge will start at point B, where Dwayne is standing, and end at point C, where Keisha is standing. Lonzell walks to point D and then walks parallel to the river until he reaches point E, where he sees Dwayne and Keisha are aligned. Why is the distance from E to B the length of the new bridge?
