Given a rectangle with sides eight and three, and a parallelogram with sides two and five, what is the difference in their perimeters?
Before we can work out the difference in the perimeters, we must first work out the perimeters of the rectangle and parallelogram individually. Let’s begin with the rectangle.
We’re told that the rectangle has side lengths of eight and three units. Opposite sides in a rectangle are of equal length. So our rectangle has two sides of length eight and two sides of length three. Its perimeter, which is the distance all the way around its edge, is found by adding eight, three, eight, and three. Eight plus three is 11. So the total perimeter of the rectangle is 22 units.
Next, we consider the parallelogram, which has sides of lengths two and five. Opposite sides in a parallelogram are also of equal length. So the parallelogram has two sides of length two and two sides of length five. Its perimeter is therefore two plus five plus two plus five. Two plus five is seven. So the perimeter of the parallelogram is 14 units.
To work out the difference in their perimeters, we subtract the smaller perimeter, that’s the perimeter of the parallelogram, from the larger perimeter, that’s the perimeter of the rectangle, giving 22 minus 14. 22 minus 14 is eight.