In the given figure, ABCD is a cyclic quadrilateral in which BC = CD and CBD = 35°. Then, BAD = ?

Given: CB = CD and CBD = 35°


Consider ΔBCD


Here,


CB = CD (given)


CBD = CDB = 35° (In a triangle, angles opposite to equal sides are equal)


By angle sum property


BCD + CBD + CDB = 180°


BCD + 35° + 35° = 180°


BCD = 180° – 35° – 35° = 110°


We know that,


In a cyclic quadrilateral opposite angles are supplementary


BCD + BAD = 180°


110° + BAD = 180°


BAD = 180° 110° = 70°


BAD = 70°

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