Question

When do you say that a given quadrilateral is a parallelogram?

Answer 1

Theorem : If in a quadrilateral, each pair of opposite angles is equal, then it is a parallelogram. Given : ABCD is a quadrilateral in which ∠A = ∠C and ∠B = ∠D. We know that the sum of the angles of a quadrilateral is 360o.

Explanation:

hope that helps