解三角形 （1）已知a=49cm,b=26cm，C=107°， （2）c=55cm,a=58cm,B=66° (3)a=9cm,b=10cm,c=15cm

(1)c²=a²+b²-2abcosC=3821.96 c=61.8 a/sinA=b/sinB=c/sinC=64.62 sinA=0.7583 sinB=0.4024 A=49° B=24° c=61.8cm (2)b²=a²+c²-2accosB=3794.02 b=61.6 a/sinA=b/sinB=c/sinC=67.