On a miter saw, when you're cutting a 90 degree cut, the miter saw reads zero. On a protractor, it reads 90. So it's an unending source of confusion for people. RON HAZELTON: So Mark, show me how it works.
A ruler is used to measure units of length, inches, feet and yards. Standard rulers have inches on one side and centimeters on the other. A typical ruler measures up to 12 inches, and is equivalent to 30.48 centimeters. This is also equivalent to 1 foot. Each inch on a ruler has markings in between that are a fraction of an inch.
The side of a square is the square root of the area, in this case the square root of 9 square inches, which is 3 inches. Now think about the rectangle again. What we just counted was the side of a square that made up one half of the rectangle you wanted to calculate the area of. So the shorter side of the rectangle is the same as our square, and the longer side is double the length. So the width of the rectangle is 3 inches, and the length is 2 * 3 inches = 6 inches. Or: Area = length x width (A=lw) Area = 18 (in2) Width = w Length = twice width (2w) 18 = (2w)w 18 = 2w2 9 = w2 3 = w The width is 3 in., the length (2w) is 6 in.