The perimeter of a rectangle can be determined by adding the four sides together. The sum of the shorter sides is x+x, and the sum of the longer sides is (x+7) + (x+7). If these are added, we'll get the perimeter of the rectangle.
We are going to determine the length of the rectangle's sides. Thus, we must determine the value of x. Previously, we've written an expression representing the perimeter of the rectangle. Since the perimeter is equal to 66, we can write the following equation.
Now, we can solve it for x.