To obtain the perimeter of a rectangular base, add all the sides using the formula P = 2l + 2w, where P is the perimeter, l is the length, and w is the width. You need ruler or a tape measure, a pen and a piece of paper. The process takes just a few minutes.Continue Reading
The base of a rectangular prism has four sides. The two lengths of the base are equal and the two widths are equal as well. Measure the sides using a ruler or a tape measure.
Multiply the length by 2. Do the same with the width.
Add the values obtained from the previous step. The sum is the perimeter of the base of a rectangular prism.