Verified answer

Step-by-step explanation:

Here OB = OC (Radii of same circle)

ang OBC = ang OCB (Angle opp. to equal sides)

180 - OBC = 180 - OCB (Subtracting both sides by 180⁰)

ang OBA = ang OCD

Now, In triangle OBA and OCD

ang OBA = ang OCD(proved)

0A = OD

OB = OC

so, triangle oba congruent to OCD

so ab=cd