Thread: how fast does the shadow move

A street light is at the top of a 18 ft tall pole. A woman 6 ft tall walks away from the pole with a speed of 8 ft/sec along a straight path. How fast is the tip of her shadow moving when she is 40 ft from the base of the pole?

can someone help me set this up

Here is a diagram that should help


Use similar triangles to find a relationship between x and y.
I hope this helps