弦长L=7米弓高H=1米弧长C是多少?
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)
=1/2+7^2/(8*1)
=6.625米
A=2*ARC SIN((L/2)/R)
=2*ARC SIN((7/2)/6.625)
=63.78度
C=π*R*A/180=π*6.625*63.78/180=7.7349米
弦长L=7米弓高H=1米弧长C是多少?
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)
=1/2+7^2/(8*1)
=6.625米
A=2*ARC SIN((L/2)/R)
=2*ARC SIN((7/2)/6.625)
=63.78度
C=π*R*A/180=π*6.625*63.78/180=7.7349米