要分二种情况,弦AB和AC是圆心的同侧和异侧.
1、异侧,
从A作直径AD,连结BD,CD,根据半圆上圆周角是直角性质,
△ABD和△ACD都是RT△,
AD==2,AB=√2,BD=√2,
CD=√(2^2-3)=1,
〈CAB=75°,
S作OE⊥AB,OE=1/2R=1/2,AE=√3/2,
S△AOB=√3/4,
S扇形AOB=π*120/360=π/3,
S弓形AB=π/3-√3/4,
S△AOC=1/2,
S扇形AOC=π/4,
S弓形AC=π/4-1/2
S△ABC+BD弓形=π-(π/3-√3/4)-(π/4-1/2)
=5π/12+√3/4+1/2.
第二种情况在同侧,
S△ABC=AC*ABsin15°/2=√3*√2*(√6-√2)/4
=(3-√3)/2.
S△BOE=1*1*sin30°/2=1/4,
S扇形BE=π*30/360=π/12,
S弓形BE=π/12-1/4,
S△AOE=1/2,
S扇形AE=π/4,
S弓形AE=π/4-1/2,
S△ABC+BD弓形=圆面积-弓形BE-弓形AE=π-(π/12-1/4)-(π/4-1/2)
=2π+3/4.