How to Find the Ratio of a Rectangle in Geometry

By Carter McBride
Ratios with rectangles deal with the measurement of one side compared to the other.

Rectangles have four sides, and generally the adjacent sides are not equal. Knowing the measurements of the two sides allows you to create a ratio of the rectangle. This tells you how much bigger one side is compared to the other side. This is used in basic geometry and helps students understand properties of a rectangle. If you know the ratio of a rectangle and know the measurement of one side, you can calculate the adjacent side.

Measure your rectangle's sides. For example, assume your rectangle has a side of 8 inches and another of 4 inches.

Set up a ratio where your large side is on top of the fraction and the smaller side is on the bottom of the fraction. In the example, 8 inches / 4 inches.

Divide the ratio, then set the bottom number to one. In the example, 8 divided by 4 equals 2. So your ratio is 2 to 1.

Tip

Rectangles with the same length-to-width ratios are considered similar.

About the Author

Carter McBride started writing in 2007 with CMBA's IP section. He has written for Bureau of National Affairs, Inc and various websites. He received a CALI Award for The Actual Impact of MasterCard's Initial Public Offering in 2008. McBride is an attorney with a Juris Doctor from Case Western Reserve University and a Master of Science in accounting from the University of Connecticut.