由正弦定理:a/sinA=b/sinB=c/sinC;
(1)因为:A=30°,C=45°,a=√2;所以:√2/sin30°=c/sin45°,解得:c=2;
因为:B=180°-30°-45°=105°
因为sinB=sin(60°+45°)=sin60°cos45°+cos60°sin45°=(√2+√6)/4;
由正弦得:a/sinA=b/sinB,即:√2/sin30°=b/sin105°,得b=1+√3;
(2)因为:a=√2,b=2,A=30°;a/sinA=b/sinB即:√2/sin30°=2/sinB
所以:sinB=√2/2,所以B=45°或135°(舍),C=180°-45°-30°=105°
所以:a/sinA=c/sinC,即:√2/sin30°=c/sin105°,得c=1+√3;
(3)因为:a=1,b=√3,B=60°;
由正弦得:a/sinA=b/sinB,即1/sinA=√3/sin60°,解得:sinA=1/2;
所以A=30°或150°(舍),所以C=180°-60°-30°=90°
a/sinA=c/sinC,即1/sin30=c/sin90°,解得:c=2;