∠2+∠4=180-∠BAC=180-63=117∠4=∠3=∠1+∠2=2∠23∠2=117∠1=∠2=39∠DAC=BAC-∠1=63-39=24
=<1+=<1+(180-2*=<1+(180-2*2*<1)=180-3*<1=63<1=39
