Question

pls answer my questions

Answer 1

(12)
Here AOC and DOB are Vertically opposote angles...

i.e. AOC=DOB
→AOC=DOB=266/2=133°.

And COB is a linear pair of AOC.
So COB=180°-AOC
→COB=180-133=47°
But COB and AOD are vertically opposit angles.
→COB=AOD=47°.

(13).
Here OA,OB,OC,OD are rays Having same initial point...

I.e,AOC+COB+BOD+DOA=360°.

Given. AOC+BOC+BOD=338°
→338°+DOA=360°
→DOA=360°-338°=22°

But DOA and COB are Vertically opposite angles...
→DOA=COB=22°

DOA and AOC are in linear pair...
→AOC=180°-DOA
→AOC=180°-22°=158°

And AOC=DOB=158° (vertically opposite angles)

So... There you have it..
Hope it helps...
Regards,
Leukonov.