已知圆柱体(上大下小)上圆直径d1=45.6,下圆直径d2=40.6.垂直高度h=5(所有单位为MM)求扇形图。
扇形的大圆弧半径为R1,小圆弧半径为R2,弧所对的圆心角为A。
R1-R2=(h^2+((d1-d2)/2)^2)^0.5=(5^2+((45.6-40.6)/2)^2)^0.5=5.59017
A=PI*d1/R1=PI*d2/R2
d1/R1=d2/R2
R2=R1*d2/d1=R1*40.6/45.6
R1-R2=R1-R1*40.6/45.6=5.59017
R1*(45.6-40.6)=5.59017*45.6=254.91175
R1*5=254.91175
R1=254.91175/5=50.98mm
R2=R1*40.6/45.6=50.98*40.6/45.6=45.39mm
A=PI*d1/R1=PI*45.6/50.98=2.81006弧度=2.81006*180/PI=161度