Question

The length of a rectangle is three times it's width. If the area of the rectangle is 147 metes squared, find its perimeter.

Answer 1

`l=3w\\ lw=147\\\\ 3w\cdot w=147\\ 3w^2=147\\ w^2=49\\ w=7\\\\ l=3\cdot7=21\\\\ p=2l+2w\\ p=2\cdot21+2\cdot7\\ p=42+14\\ p=56`