Hey Guys. I'm correcting a Math test for extra points right now and I came across a question that I can't seem to figure out how to solve.

Anyone care to help?

Heres the problem:

A man 6 feet tall is walking at a rate of 5 ft/sec towards a light that is 20 feet above the ground. When he is 10 feet from the base of light, at what rate is the tip of his shadow changing.

I know how to draw the picture and thats about it haha. Where do I start?

Any help?

Thanks!

Aaron Snyder