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28 votes
28 votes
In quadrilateral ABCD m ZA-90° m / C = 50° and m B = m 2D. Find the degree measure of Z B.

User Sooyeon
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1 Answer

25 votes
25 votes

The sum of the internal angles in a quadrilateral is equal to 360, therefore:


\begin{gathered} \angle A+\angle B+\angle C+\angle D=360 \\ 90+\angle B+50+\angle B=360 \\ 140+2\angle B=360 \\ 2\angle B=360-140 \\ 2\angle B=220 \\ \angle B=(220)/(2) \\ \angle B=110 \end{gathered}

User Sangretu
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