圆弧的弦长4.4米 弧高0.4米求弧长?

1个回答

  • 圆弧的弦长L=4.4米 弧高H=0.4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*H*R+H^2+L^2/4

    2*H*R=H^2+L^2/4

    R=H/2+L^2/(8*H)

    =0.4/2+4.4^2/(8*0.4)

    =6.25米

    A=2*ARC SIN((L/2)/R)

    =2*ARC SIN((4.4/2)/6.25)

    =41.219度

    =41.219*PI/180

    =0.719414弧度

    C=R*A=6.25*0.719414=4.496米