已知弧长与弦长,求弓形面积,例如弦长为L=6,弧长为C=2π,求弓形面积S?
弧半径为R,弧所对的圆心角为A.
L=6,C=2π=6.28319
Rn+1=(1+(L-2*Rn*SIN(C/(2*Rn)))/(L-C*COS(C/(2*Rn))))*Rn
R0=5
R1=5.6661
R2=5.9574
R3=5.9992
R4=6
R5=6
R=6
A=C/R=2π/6=π/3=(π/3)*(180/π)=60度
S=PI*R^2*A/360-R*R*COS(A/2) /2
=PI*6^2*60/360-6*6*COS(60/2)/2
=3.261