mural should be placed. 17 The scale ratio for two similar rectangles is 1 : 2. The sum of their areas is 40 cm. Determine the area of each rectangle. 13. Determine the scale factor that relates each pair of similar shapes. E a H A D B C F G area = 5.00 cm2 area = 11.25 cm2 b) area = 3.00 cm2 area = 12.00 cm2