数学求圆的公式计算R=3CM 求C D=4CM 求C R=2CM 求S D=6CM 求S C=12.56CM 求S C=

R=3CM C=2∏R=6∏cm D=4CM C=∏D=4∏cm R=2CM S=∏R^2=4∏cm^2 D=6CM S=∏(D/2)^2=9∏cm^2 C=12.56CM R=C/2∏=2 S= ∏R^2=4∏cm^2 C=314M R=C/2∏=100 S=∏R^2=10000∏m^2 C=18.84CM R=C/2∏=6 S=∏R^2=36∏cm^2 C=18.84DM R=C/2∏=6DM D=2R=12DM C=9.42M R=C/2R=3M S=∏R^2=9∏m^2 D=3DM R=D/2=1.5M S=∏R^2=2.25∏dm^2