弦长5.3米,求弧长这个弧要用铁板焊接,像个帽子一样,求怎么放样

弦长L=5.3米,高H=1米,求弧长C?
弧半径为R,弧所对的圆心角为A.
R^2=(R-H)^2+(L/2)^2
R^2=R^2-2*R*H+H^2+L^2/4
2*R*H=H^2+L^2/4
R=H/2+L^2/(8*H)
=1/2+5.3^2/(8*1)
=4.011米
A=2*ARC SIN((L/2)/R)
=2*ARC SIN((5.3/2)/4.011)
=82.698度
C=PI*R*A/180=PI*4.011*82.698/180=5.79米
弦长L=5.3米,高H=2米,求弧长C?
弧半径为R,弧所对的圆心角为A.
R^2=(R-H)^2+(L/2)^2
R^2=R^2-2*R*H+H^2+L^2/4
2*R*H=H^2+L^2/4
R=H/2+L^2/(8*H)
=2/2+5.3^2/(8*2)
=2.756米
A=2*ARC SIN((L/2)/R)
=2*ARC SIN((5.3/2)/2.756)
=148.17度
C=PI*R*A/180=PI*2.756*148.17/180=7.126米

弦长5.3米，高1米，弧长5.7896