已知弦长为L=6500,弧高为H=650,求半径R和弧长C?弧所对的圆心角为A.R^2=(R-H)^2+(L/2)^2R^2=R^2-2*R*H+H^2+L^2/42*R*H=H^2+L^2/4R=H/2+L^2/(8*H) =650/2+6500^2/(8*650)=8450A=2*ARC SIN((L/2)/R)=2*ARC SIN((6500/2)...