已知弧长为C=4.所对圆心角为A=120°.求所对的弦长L?
圆半径为R.
A=120°
=120*PI/180
=2.0944弧度
R=C/A
=4/2.0944
=1.9099
L=2*R*SIN(A/2)
=2*1.9099*SIN(120°/2)
=3.308