已知弧长C=480,弦长L=400,求弧度A?
弧半径为R.
Rn+1=(1+(L-2*Rn*SIN(C/(2*Rn)))/(L-C*COS(C/(2*Rn))))*Rn
R0=239
R1=233.459
R2=233.749
R3=233.75
R4=233.75
R=233.75
A=C/R=480/233.75=2.053476弧度=2.053476*180/π=117.656度