过角平分线的交点,做三边的垂线,AE,AF,AG
AE=AF=AG
S=1/2AE*AB+1/2AF*AC+1/2AG*BC
=1/2(AE*AB+AF*AC+AG*BC)
=1/2(AE*(AB+AC+BC))
=1/2AE*周长
=1/2*2*18
=18
过角平分线的交点,做三边的垂线,AE,AF,AG
AE=AF=AG
S=1/2AE*AB+1/2AF*AC+1/2AG*BC
=1/2(AE*AB+AF*AC+AG*BC)
=1/2(AE*(AB+AC+BC))
=1/2AE*周长
=1/2*2*18
=18