m(AOB)=180°
daca OT bis AOE
m(AOT)=20° rezulta ca si m(TOE)=20°
OD bis EOC
m(DOC)=40° rezulta ca si m(EOD)=40°
m(EOC)=m(EOD)+m(DOC)=40+40=80°
m(AOE)=m(AOT)+m(TOE)=40°
m(TOD)=m(TOE)+m(EOD)=20+40=60°
m(BOC)=180-m(AOE)-m(EOC)=180-40-80=60°
OP bis =m(COP)=m(POB)=60:2=30°
m(DOP)=m(DOC)+m(COP)=40+30=70°