Four squares A, B, C and D are placed as shown in the figure. The perimeter of square A is 12 cm and the perimeter of square D is 60 cm. Then the area of ??the shaded part will be

Known: The perimeter of A is 12 cm, the side length of ∴A = 3 cm

It is known: the perimeter of D is 60 cm, the side length of ∴D = 15 cm

It is known that: the side length of B + the side length of C = 15 cm

And: the side length of C - the side length of B = 3 cm

Solution: The side length of C = 9 cm,

The shaded area of ??C = 40.5 square centimeters

The side length of B = 6 cm,

B The shadow area=18 cm

∴The total shadow area=40.5+18=58.5 (square centimeters)