how do i check camber?

I read somewhere on the internet a simple way to check camber. you had to measure 8 inches or something from center of rim using a square and other tools. i cant remember exactly how to do it and i was wondering if anyone else knows how?

You want to make a triangle using the wheel and ground. Take a ruler and measure from the ground up to the center of the wheel. Then measure from the ruler to the center of the wheel. Then measure from the center of the wheel to the bottom of the ruler. Figure out what angle the bottom angle is to figure out camber. Remember Math 101 :)