弦长L=1.885弦高H=0.018求半径R?
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)
=0.018/2+1.885^2/(8*0.018)
=24.684((1.885/2)*(1.885/2)/0.018)+0.018)/2 =24.648R=H/2+L^2/(8*H)=((L/2)^2/H+H)/2