Polygon angles investigation

A complete lesson with a focus on angles as variables. Basically, pupils investigate what angle relationships there are when you overlap a square and equilateral triangle. A good opportunity to extend the topic of polygons, consider some of the dynamic aspects of geometry and allow pupils to generate their own questions. Prior knowledge of angles in polygons required.

Activities included:

Starter:
A mini-investigation looking at the relationship between two angles in a set of related diagrams, to recap on basic angle calculations and set the scene for the main part of the lesson.

Main:

• A prompt (see cover image) for pupils to consider, then another prompt for them to work out the relationship between two angles in the image.
• A slide to go through the answer (which isn’t entirely straight forward), followed by two animations to illustrate the dynamic nature of the answer.
• A prompt for pupils to consider how the original diagram could be varied to generate a slightly different scenario, as a prompt for them to investigate other possible angle relationships. I’ve not included answers from here, as the outcomes will vary with the pupil. The intention is that pupils then investigate for themselves.

Plenary:
Another dynamic scenario for pupils to consider, which also reinforces the rules for the sum of interior and exterior angles.

Please review if you buy as any feedback is appreciated!