The purpose of this lesson is to explore other attributes of quadrilaterals.

Included is a YouTube video to support Grade 5 Blended Learning Math - Unit 6.4: Geometry - Other Attributes of Quadrilaterals.

The purpose of this lesson is to introduce the grade 6 math unit on measurement involving angles and polygons.

Included is a YouTube video to support Grade 6 Blended Learning Math - Unit 4.0: Measurement - Angles and Polygons: Introduction.

The purpose of this lesson is to investigate angles in a quadrilateral.

Included is a YouTube video to support Grade 6 Blended Learning Math - Unit 4.7: Measurement - Angles and Polygons: Investigating Angles in a Quadrilateral.

This is a reasonably direct task aimed at having students use previously-derived results to learn new facts about parallelograms, as opposed to deriving them from first principles. The solution provided (among other possibilities) uses the SAS trial congruence theorem, and the fact that opposite sides of parallelograms are congruent.