Question

In a parallelogram ABCD, angle B = 80° find A, D and C.​

Answer 1

Angle B = Angle D (Opp angles of a //gm are equal) - 1

Thus, Angle D = 80°

Let angles A and C be X (From 1)

80 + 80 + X + X = 180

160 + 2X = 180

2X = 180 - 160

2X = 30

X = 30

X = 30 ÷ 2

X = 15

Answer 2

C= A = 180°- 80°= 100° [since C,A and B are cointerior angles.]

D = 80° [since opposite angles of a parallelogram are equiangular