Question

in figure 6, find the value of a,b,c and d, given that ABCD is a parallelogram.

Answer 1

here a=115
b=25
c=40
and d=50

Answer 2

here a=115 (oppo angles)
since AC is a strait line so c=180-140=40 (angle on strait line)
since it is a parallelogram so opp sides are// and angles are alternate
so d=50 (inte alternate)
now since c=40
so angleCAB=40 (alternate)
so in that triangle angleCAB=40 and let the meeting point of the diagonal be x
so since angleAXB=115 (as given)
so angleABX=180-(115+40)=180-155=25 (angle sum property)
so angleBDC=b=25 (alternate angle)