Quadrilateral ABCD is inscribed in a circle. What is the measure of angle A?

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1 Answer
May 17, 2018

133^o133o

Explanation:

the quadrilateral is a cyclic quadrilateral, and its fundamental property is that the opposite angles are supplementary

ie they add up to 180^o180o

:.4x+5+x+15=180

5x+20=180

5x=180-20=160

x=160/5=32

:. < A=4xx32+5=128+5=133