a)∡AOD=360-∡AOB-∡BOC-∡COD
∡AOD=40°
b)∡A=(BC+CD)/2 = (60+120)/2 = 90°
∡B=(CD+AD)/2 = (120+40)/2 = 80°
∡C=(AD+AB)/2 = (40+140)/2 = 90°
∡D=(AB+BC)/2=(140+60)/2 = 100°
c)∡CAB=BC/2=30°
∡CAD=∡DOC/2 = 60°
∡BDC=∡COB/2 = 30°
∡BDA=∡AOB/2=70°
∡ACD=∡DOA/2=20°
∡ACB=∡AOB/2=70°
∡DBC=∡DOC/2=60°
∡DBA=∡DOA/2=20°
sper ca n-am omis ceva