ABCD is a cyclic quadrilateral and AB=AC,if ACB=70* find BDC - Maths - Circles

Question

ABCD
is a cyclic quadrilateral and AB=AC,if <ACB=70* find < BDC

Sameer N · Accepted Answer

Given : AB=AC
<ACB = <ABC ( angle opposite to equal side is equal)
<ABC = 70 *
Using angle sum property in Triangle ABC
<BAC +<ACB+<ABC = 180
<BAC +70 +70 = 180
<BAC = 40

<BAC + <BDC = 180 ( angles of cyclic quadrilateral is
supplementary )
40 + <BDC =180
<BDC = 140

ABCD is a cyclic quadrilateral and AB=AC,if <ACB=70* find < BDC