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

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
(4)a=31cm,b=42cm,c=27cm

人气：434 ℃　时间：2020-04-30 04:35:25

解答

(1)c²=a²+b²-2abcosC=3821.96 c=61.8a/sinA=b/sinB=c/sinC=64.62sinA=0.7583 sinB=0.4024A=49° B=24° c=61.8cm(2)b²=a²+c²-2accosB=3794.02 b=61.6a/sinA=b/sinB=c/sinC=67.42sinA=...