弦长L=12米,拱高H=1.3米,求 弧长C?
弧半径为R,弧所对的圆心角为A.
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)
=1.3/2+12^2/(8*1.3)
=14.4962米
A=2*ARC SIN((L/2)/R)
=2*ARC SIN((12/2)/14.4962)
=48.9度
C=π*R*A/180=π*14.4962*48.9/180=12.372米
弦长L=12米,拱高H=1.3米,求 弧长C?
弧半径为R,弧所对的圆心角为A.
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)
=1.3/2+12^2/(8*1.3)
=14.4962米
A=2*ARC SIN((L/2)/R)
=2*ARC SIN((12/2)/14.4962)
=48.9度
C=π*R*A/180=π*14.4962*48.9/180=12.372米