Yao and Dewayne are standing 3 feet apart. When Earl looks at Dewayne, he notices that the top of his head completely blocks off Yao's. If Earl's eyes are 5'3" off the ground, if Dewayne is 6'3" tall, and Yao is 7'6" tall, how far from Dewayne is Earl standing?
a diagram would be very helpful
similar triangles
(90" - 63") / (36" + x) = (75" - 63") / x