The perimeter of a rectangular photo frame is 90 cm. The length is twice the width. What are the length and width of the frame? (Hint: The formula for perimeter is where w is the width, l is the length, and P is the perimeter.)
The formula for perimeter of a rectangle is 2(w + l) = P Since the length of the frame is twice its width, 2(w + 2w) = 90cm. Thus, 2(3w) = 90cm 6w = 90cm Therefore, w = 90/6. w = 15
