State which theorem you can use to show that the quadrilateral is a parallelogram.

Question

It includes a picture of a shape with 4 sides

Answer 1

Without the picture we can’t tell which theorem best suits the problem.

Here are some that might apply:

Adjacent vertex angles are supplementary (add up to 180°).

Both pairs of opposite angles are equal.

Alternate angles of a diagonal are equal.

Area of parallelogram is product of the base length and perpendicular height.

A diagonal splits the parallelogram into two congruent triangles.