Solution: As can be seen from the figure, the difference of blank area is equal to the sum of two sector areas minus the square area.

S spatial difference =2S fan-s positive.

= 2X r？ /4-4x4 R= side length =4cm

= 味味 r? /2 one 16

= 4? /2 one 16

=8 Wuyi 16

Material ≈8x3. 14- 16

=25. 12- 16

=9. 12 (square centimeter)

A: The difference of blank area in the figure is 9. 12 cm2.