Question

Can a quadrilateral abcd be a parallelogram if​

Answer 1

Answer:

Yes, a quadrilateral ABCD be a parallelogram if ∠D + ∠B = 180° but it should also fulfilled some conditions which are: The sum of the adjacent angles should be 180°. ... Draw a rough figure of a quadrilateral that is not a parallelogram but has exactly two opposite angles of equal measure

(i) AD = BC

[Since opposite sides of a parallelogram are equal]

(ii) DCB = DAB

[Since opposite angles of a parallelogram are equal]

(iii) OC = OA

[Since diagonals of a parallelogram bisect each other]

(iv) DAB + CDA =  180

[Adjacent angles in a parallelogram are supplementary]