一个圆被一条直线所截,截得的弦长等于半径,截后的面积怎么求?设圆半径为R,已知弦长b=R；那么该弦所对的圆心角θ=π/3；弓形的高h=R-Rcos(π/6)=R(1-√3/2)；于是弓形的面积=(1/2)R²[π/3-sin(π/3)]=(1/2)R...