1.A=60度,B=45度,c=20cm
C=180-60-45=75
a/sinA=c/sinC;
a=c*sinA/sinc=20*sin60/sin75=19
b/sinB=c/sinC;
b=c*sinB/sinC=20*sin45/sin75=15
2.a/sinA=b/sinB;
sinA=a*sinB/b;
sinA=20*sin30/11=1/110;
A=65C=180-65-30=85
c/sinC=b/sinB;
c=b*sinC/sinB=11*sin85/sin30=22