Given two crossed Ladders resting against two buildings, what is the distance between the buildings? Let the height at which they cross be and the lengths of the Ladders and . The height at which touches the building is then obtained by solving

Call the horizontal distance from the top of to the crossing , and the distance from the top of , . Call the height at which touches the building . There are solutions in which , , , , , and are all Integers. One is , , , and .