Area P6 2010 SA2 Nanyang P1 Q30

The figure below is formed by stacking 4 pieces of square paper one on top of another. The papers have different prints and sizes of sides 3cm, 4cm, 5cm and 6cm. The 6-cm piece is placed at the bottom of the stack, followed by the 5-cm piece, then the 4-cm piece and the 3-cm piece is placed right on top.

Find the sum of the area A and B. (ans : 8 cm2)

6 - 1 = 5

5 - 3 = 2

6 - 4 = 2

2 x 2 = 4

4 x 2 = 8 cm2