Rectangle Perimeter Problem: Finding the Distance Around a 21-Square-Unit Shape

Question

If the area of the rectangle is 21.

Determine the perimeter of the rectangle.

00:00 Determine the perimeter of the rectangle

00:03 The perimeter of the rectangle equals the sum of its sides

00:10 Opposite sides are equal in a rectangle

00:15 Substitute the relevant values into the formula according to the given data and proceed to solve for the perimeter

00:21 This is the solution

Given that in a rectangle every pair of opposite sides are equal to each other, we can state that:

$AB=CD=7$

$AC=BD=3$

Now let's add all the sides together to calculate the perimeter:

$3+7+3+7=6+14=20$