Posted by ganga on Tuesday, February 5, 2013 at 5:45am.
ABCD is a parallelogram the angle bisector of angleA and angleD intersect at O. Find the measure of angle AOD

maths  Reiny, Tuesday, February 5, 2013 at 8:55am
Did you make your sketch?
let angle A be 2x
let angle D be 2y
because of the parallel lines,
2x + 2y = 190
x + y = 90
after bisection of angle A and D
look at triangle AOD
we have x + y + angle AOD = 180
90 + angle AOD = 180
angle AOD = 90°