圆面积=πx2x2=4π1:3 :2 :4360°x1/(1+3+2+4)=360°x1/10=36°,面积=4πx1/10=2π/5;360°x3/10=108°,面积=4πx3/10=6π/5;360°x2/10=72°,面积=4πx2/10=4π/5;360°x4/10=144°,面积=4πx4/10=8π/5;...