已知弓形的弦长L=12cm弧长C=26cm求弦高H?
弧半径为R,弧所对的圆心角为A.
Rn+1=(1+(L-2*Rn*SIN(C/(2*Rn)))/(L-C*COS(C/(2*Rn))))*Rn
R0=7
R1=6.483
R2=6.55
R3=6.552
R4=6.552
R=6.552cm
A=C/R
=26/6.552
=3.968254弧度
=3.968254*180/PI
=227.36度
H=R-R*COS(A/2)
=6.552-6.552*COS(227.36/2)
=9.184cm