1,1/2X3.14X5X5+1/3X5X5=1.9X25=47.5
2,3.14X3X3-2(1/4X3X3-1/2X3X3)=18
3,(1/4X3.14X6X6-1/2X6X6)-(1/4X3.14X3X3-1/2X3X3)=7.695
表达不好表达,所以只好写了公式,没有解释为什么.我相信你看得懂的.
1,1/2X3.14X5X5+1/3X5X5=1.9X25=47.5
2,3.14X3X3-2(1/4X3X3-1/2X3X3)=18
3,(1/4X3.14X6X6-1/2X6X6)-(1/4X3.14X3X3-1/2X3X3)=7.695
表达不好表达,所以只好写了公式,没有解释为什么.我相信你看得懂的.