已知圆的半径是R=3478.弦长是L=3000求弧长C?
弧所对的圆心角为A.
A=2*ARC SIN((L/2)/R)
=2*ARC SIN((3000/2)/3478)
=51.098度
=51.098*PI/180
=0.891827弧度
C=R*A=3478*0.891827=3101.78