小学六年级数学圈练习题

==44*3.14

=138.16cm^2

12/2 = 5厘米

8/2 = 4厘米

(5*5-4*4)*3.14

=9*3.14

=28.26cm^2

50+2 = 52厘米

(52*52+50*50)*3.14

=204*3.14

=540.56cm^2

10/2 = 5厘米

5*5*3.14=78.5cm^2

10*12-7805

=120-78.5

=41.5cm^2

2*2*3.14/2

=12.56/2

=6.28cm^2

(6.28-2.28)*2/4

=4*2/4

2厘米