已知弧长C=3163,拱高H=150,求弦长L?
弧半径为R,弧所对的圆心角为A.
Rn+1=(1-(Rn*COS(C/(2*Rn))-Rn+H)/((C/2)*SIN(C/(2*Rn))-H))*Rn
R0=8000
R1=8289.54
R2=8311.9
R3=8312.02
R4=8312.02
R=8312.02
A=C/R=3163/8312.02=0.38053弧度=0.38053*180/PI=21.8度
L=2*R*SIN(A/2)
=2*8312.02*SIN(21.8/2)
=3143.95