A=1弧度所对弦长为L=2,圆心角所夹扇形面积S?
弧半径为R.
A=1弧度=1*180/PI=57.296度
R=(L/2)/SIN(A/2)
=(2/2)/SIN(57.296/2)
=2.0858
S=PI*R^2*A/(2*PI)
=R^2*A/2
=2.0858^2*1/2
=2.175