In the given figure, is a chord of a circle with center and is produced to such that Also, is joined and produced to meet the circle in If and prove that

Given, OB = OC


Then, BOC = BCO =


External OBA = BOC + BCO = (2y)°


Now,


OA = OB


Then, OAB = OBA = (2y)°


External AOD = OAC + ACO


= OAB + BCO = (3y)°


= (3y)°[Given ]


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