How to Find the Perimeter of a Parallelogram

By Teresa J. Siskin; Updated April 24, 2017
A parallelogram includes the rhomboid, rhombus, square and the rectangle.

The perimeter of a parallelogram is equal to sum of its side and base lengths multiplied by two. In equation form, this is represented as P = 2(a+b), where P represents the perimeter, a is the side length and b is the base length. You can find the perimeter of a parallelogram provided you have both the side and base measurements.

Sample Perimeter Calculation

Given a parallelogram with a side length of 10 and a base length of 20, you can enter these values into the above equation, P = 2 (10 + 20), which results in 60. You can check the accuracy of your computation by adding up the four sides of your parallelogram. Since opposite sides are always equal to each other in length you know both side lengths are 10 and both base lengths are 20. These four sides added together or 10+10+20+20 = 60.

About the Author

Teresa J. Siskin has been a researcher, writer and editor since 2009. She holds a doctorate in art history.