ВС2=АС2+АВ2-2АС•АВ•CosA
2AC•AB•CosA=AC2+AB2-BC2
CosA=(AC2+AB2-BC2)/2AC•AB
CosA=(324+400-196)/2•18•20=0,73, A=44°
BC/SinA=AC/SinB
SinB=AC•SinA/BC
SinB=18•0,69/14=0,89
B=63°
C=180°-44°-63°=73°
ВС2=АС2+АВ2-2АС•АВ•CosA
2AC•AB•CosA=AC2+AB2-BC2
CosA=(AC2+AB2-BC2)/2AC•AB
CosA=(324+400-196)/2•18•20=0,73, A=44°
BC/SinA=AC/SinB
SinB=AC•SinA/BC
SinB=18•0,69/14=0,89
B=63°
C=180°-44°-63°=73°