Hello
In the top figure,
Area of blue rectangle = z × 2z = 2z2
Area of orange rectangle = 2z × 8 = 16z
Area of both rectangles = 2z2 + 16z
In the bottom figure,
Area of both rectangles = (z + 8) × 2z = z(2z) + 16z = 2z2 + 16z
Written on Nov. 21, 2017, 6:11 p.m.