知道弧长C=1500,弓高H=450,怎样求弦长L?
弧半径为R.弧所对饿圆心角为A.
Rn+1=(1-(Rn*COS(C/(2*Rn))-Rn+H)/((C/2)*SIN(C/(2*Rn))-H))*Rn
R0=500
R1=524.54
R2=526.04
R3=526.05
R4=526.05
R=526.05
A=C/R=1500/526.05=2.85144弧度=2.85144*180/PI=163.375度
L=2*R*SIN(A/2)=2*526.05*SIN(163.375/2)=1041.05