Plz solve 1st sum Share with your friends Share 1 Neha Sethi answered this Dear student In △BOC and △CODBC=DC since quadrilateral is equilateralOC=OC commonOB=OD (given)So,△BOC≅△DOC By SSS⇒∠BOC=∠DOC [By CPCT] ....(1)Similarly, we can prove that ∠BOA=∠DOA ...(2)Now, as we know that angles around a point add to 360°Hence ∠BOC+∠DOC+∠BOA+∠DOA=360°⇒2∠DOC+∠DOA=360° using 1 and 2⇒∠DOC+∠DOA=180°This means ∠AOC=180° which means A,O,C are in same straight line. Regards 1 View Full Answer Qwertyuiop answered this Try to prove that AOC os 180° 0