So first to find the value of x you would set up the equation 486 = (6x)x because the area of a rectangle is equal to length times width. So I did length (6 times the width (6x)) times width (x) equals the area (486). You then solve by distributing, so you get 486 = 6x², then divide by 6 to get 81 = x². You then square root to get x = 9. Then you find the length and width values. Length is 6x, so 6(9) or 54. Width is x so width is 9. Then the perimeter is length + width + length + width or 54 + 9 + 54 + 9 or 126. The perimeter is 126.
