过圆心O作OD⊥弦AB于D.连接OA. 则 OA = r .AD=AB/2=1,所以r = (1/sin1)所以扇形的弧长l=r * 2= 2/sin1S = (1/2) * r * l = (1/2)*(1/sin1)*(2/sin1)=1/sin²1约为1.412
2弧度的圆心角所对的弦长为2，则这个圆心角所夹的扇形面积数值是？2/sin²1弧度 1/r=sin1弧度
