已知弧长C=2.14,弦长L=2.04,求弓形面积S?
弧半径为R,弧所对的圆心角为A。用下式来求得R
Rn+1=(1+(L-2*Rn*SIN(C/(2*Rn)))/(L-C*COS(C/(2*Rn))))*Rn
R0=2
R1=2.006
R2=2.006
R=2.006
A=C/R=2.14/2.006=1.0667996弧度
S=π*R^2*A/(2*π)-(L/2)*(R^2-(L/2)^2)^0.5
=R^2*A/2-(L/2)*(R^2-(L/2)^2)^0.5
=2.006^2*1.0667996/2-(2.14/2)*(2.006^2-(2.14/2)^2)^0.5
=0.3308