Respuesta :

Answer is angAOC=90

Is A O B is in one line so
2a+62+54-a+5a-20=180
6a=180-62+20-54=84
a=14
angAOC= 2a+62=90
angCOD=54-a=40
angDOB=5a-20=50
SO angAOC is the biggest