# HSG-CO.C.11

Prove theorems about parallelograms. Theorems include: opposite sides are congruent, opposite angles are congruent, the diagonals of a parallelogram bisect each other, and conversely, rectangles are parallelograms with congruent diagonals.

## Tasks

Midpoints of the Sides of a Paralellogram

Is this a parallelogram?

Parallelograms and Translations

Congruence of parallelograms