SOLUTION: ABCD is a parallelogram with angle a= 80 degrees.the internal bisectors of angle b and c meet at o. find angle BOC

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Question 1081968: ABCD is a parallelogram with angle a= 80 degrees.the internal bisectors of angle b and c meet at o. find angle BOC
Answer by KMST(5328) About Me  (Show Source):
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In a parallelogram ABCD, angles A and C are congruent,
and angles B and D are supplementary to angle A.
In this case, it means that the parallelogram's
angle at B (ABC) measures 180%5Eo-80%5Eo=100%5Eo ,
and the angle at C (BCD) measures 80%5Eo .
We know how to fight our the measures
of two of the angles in triangle BCO:
Angle OBC is one half of ABC,
so it measures 100%5Eo%2F2=50%5Eo .
Angle OCB is one half of BCD,
so it measures 80%5Eo%2F2=40%5Eo .
Angle BOC is the third angle in the triangle.
It's measure is
180%5Eo-%2850%5Eo%2B40%5Eo%29=180%5Eo-90%5Eo=%2890%5Eo%29