Calculate the perimeter of a rectangle if its two sides are 10 cm and the other sides are 8 cm?

The perimeter of the rectangle is equal to the sum of all sides, while the sides are pairwise equal to each other. Therefore, the formula for the perimeter of a rectangle is

P = 2 (a + b).

Example 1. The sides of a rectangle are 10 and 8 cm. Find its perimeter.

Solution. Substituting the values into the rectangle perimeter formula

P = 2 * (10 + 8) = 36 (cm) or 3600 (mm.).

Answer. The perimeter is 36 cm. 3600 (mm.).