A quadrilateral is a polygon with four sides and four angles. A parallelogram is a quadrilateral in which opposite angles are congruent. In other words, if two...
A quadrilateral is a polygon with four sides and four angles. A parallelogram is a quadrilateral in which opposite angles are congruent. In other words, if two angles of a quadrilateral are equal, then the other two angles are also equal.
A condition for a quadrilateral to be a parallelogram is that the opposite angles of the quadrilateral must be congruent.
Here's an example to illustrate this condition:
If we have a quadrilateral with angles A and B congruent to 120 degrees, and angles C and D congruent to 100 degrees, then this quadrilateral will be a parallelogram