The length of a rectangle is five times its width. If the area of the rectangle is 84m, find its perimeter.

The width of the rectangle can be represented as x, and the length can be 5x. Therefore, the area of the rectangle is x (5x) = 84.

Solve for x:

6x=84

*Divide both sides by 6*

x=14

So, the width of the rectangle is 14. To find the length, multiply 14 by 5. The length is 70.

To find the perimeter, add up the length of each side:

14+14+70+70=168

The perimeter of the rectangle is 168.