Universal understanding: When 2 straight lines cross each other, a point of symmetry is formed and 2 pairs of vertically opposite angles are formed.

Concepts: straight lines, point of symmetry, vertically opposite angles.

Essential questions:

1. Factual: what do you notice when you look at yourself on a mirror and touch your right ear?

2. Conceptual: What relationship is there between 2 points that are on both sides of a point of symmetry?

3. Debatable: Can we find a point of symmetry for any object?

Videos: Click on the title and then on the link to watch the videos

1.Angles around a point 

2.Vertically opposite angles