Draw it out first, so start out by drawing the mailbox (or just a line, it's math, not art) and then draw the 12 foot shadow. Okay, so now you know the other lamp is 10 feet tall.
The goal here is to find out the shadow of the 10 foot tall pole. So this would be x.
Making a proportion would help the most on this problem so you would say the following:
4 / 12 = 10/x, solve for x
