Geometry
posted by Anonymous .
Jonathan is 3 ft from a lamppost that is 12 ft high. The lamppost and it's shadow form the legs of a right triangle. Jonathan is 6 ft tall and Is standing parallel to the lamppost. How long is Jonathan's shadow?
I don't get how the answer is square root 180, Ryan?

Actually, it's sqrt(180) from the top of the pole to the tip of the shadow.
Using similar triangles, if the shadow is x feet long,
12/(3+x) = 6/x
12x = 18 + 6x
6x = 18
x = 3
so, the shadow is 3 feet long.