已知弦长2.6,弧长3,求弦高,角度.

已知弦长L=2.6,弧长C=3,求弦高H,角度A?
弧半径为R.
Rn+1=(1+(L-2*Rn*SIN(C/(2*Rn)))/(L-C*COS(C/(2*Rn))))*Rn
R0=1
R1=1.2534
R2=1.4755
R3=1.6065
R4=1.6406
R5=1.6424
R6=1.6424
R=1.6424
A=C/R=3/1.6424=1.826595弧度=1.826595*180/PI=104.656度
H=R-R*COS(A/2)=1.6424-1.6424*COS(104.656/2)=0.6387