the length of a rectangle is twice its width. if the perimeter of the rectangle is 54m find its area

You can denote the width of the rectangle as x,

than the length of the rectangle will be 2x

and the perimeter of the rectangle will be two length plus two width and it should be equal to 54 in

and the equation will look   2(2x)+2x=54

solving the equation 6x=54, x=9in

So the width of the  rectangle is 9in and the length is 9*2=18in

and the area of the rectangle is 9*18=162 sq in.