sina=3/√10,sinb=2/√5
tanc=-tan(a+b)
=-(tana+tanb)/(1-tanatanb)
=1
c=45°,sinc=√2/2
a=csina/sinc=(2√2)*(3/√10)/(√2/2)=6√10/5
b=csinb/sinc=(2√2)*(2/√5)/(√2/2)=8√5/5
外接圆的直径D=c/sinc==(2√2)/(√2/2)=4
sina=3/√10,sinb=2/√5
tanc=-tan(a+b)
=-(tana+tanb)/(1-tanatanb)
=1
c=45°,sinc=√2/2
a=csina/sinc=(2√2)*(3/√10)/(√2/2)=6√10/5
b=csinb/sinc=(2√2)*(2/√5)/(√2/2)=8√5/5
外接圆的直径D=c/sinc==(2√2)/(√2/2)=4