==44*3. 14
= 138. 16cm^2
12/2 = 5cm
8/2 = 4 cm
(5*5-4*4)*3. 14
=9*3. 14
=28.26cm^2
50+2 = 52 cm
(52*52+50*50)*3. 14
=204*3. 14
=540.56cm^2
10/2 = 5cm
5*5*3. 14=78.5cm^2
10* 12-7805
= 120-78.5
=4 1.5cm^2
2*2*3. 14/2
= 12.56/2
=6.28cm^2
(6.28-2.28)*2/4
=4*2/4
2 cm