So we can call the width of the rectangle x. So then the length would be 4x. The perimeter would then be 10x. Since the perimeter is 70, we can say 70 = 10x. And then simplify that to 7 = x. So the length of a rectangle would be 28 cm, and the width would be 7. So to find the area, just multiply length by width. 28*7 = 196 square cm So the rectangle's area is 196 square cm.
