已知一圆的半径为R=61.5m,弦长为L=27m,求弦所对的弧长C为多少?
弧所对的圆心角为A.
A=2*ARC SIN((L/2)/R)
=2*ARC SIN((27/2)/61.5)
=25.361度
=25.361*PI/180
=0.442629弧度
C=A*R
=0.442629*61.5
=27.2217m