Question

in the fig.shown x is the midpoint rest of the quest is in the sheet

Answer 1

angle a + b = 180 angle b = 180-a in triangle Bax ,angle xab + b+bxa= 180. angle bxa- angle a/2 ,angle bxa = angles/2 ,angle bax= bxa,. ab = bx( angles opposite to equal sides) 2 bx= BC Nd,,.
BC=ab,2ab=BC ..and BC = ad ( sides of parallelogram) therefore 2 ab= ad