21. a. Ratio of blue: green Length blue: length green 3:6 or 1:2 Width blue :width green 2:4 or 1:2 Perimeter blue: perimeter green 2+2+3+3=10: 4+4+6+6= 20 or 1 :2 Area blue: Area green 2•3=6 : 4•6= 24 or 1:4
b. The lenght, with and perimeter of the big green rectangle are double the size of the small blue rectangle. The area of the big green rectangle is 4 times greater than the area of the small blue rectangle. So if the lenghts of a rectangle are doubled the perimeter is doubled and the area is 4 times biger than the area of the doubeled rectangle.