Question

in a parallelogram ABCD, angle D= 140.find the measures of Angle A and Angle B.

Answer 1

in a parallelogram all sides are parallel so in parallelogram abcd
d and b falls in a same line ( after drawing the diagram)
therefore 180-140 = 40
40 is angle b ( reason sum of angles on a line are 180)

Answer 2

angle D = 140°, thus angle B = 140°. Sum of all angles of triangle = 360°. Thus, A+140+C+140=360°. A+B=360-280= 80°. A+B=80°. But A=B. Thus, angle A=angleC=40°.