Mathematics·Geometry·conceptual
Regular and irregular polygons
Distinguish between regular and irregular polygons based on reasoning about equal sides and equal angles
Suggested ages 9–10
Learning journey
Your child is learning to measure and work with angles using protractors, classify shapes by their properties, and understand transformations like reflections and translations while exploring how angles relate to each other.
Evidence of understanding
- Classify a set of polygons as regular or irregular
- Explain that a regular pentagon has 5 equal sides and 5 equal angles
- Identify that a rectangle is irregular (equal angles but not all equal sides) unless it is a square
Assessment prompt
If you show Regular and irregular polygons a stop sign (regular octagon) and a wonky eight-sided shape, can they explain which is regular and which is irregular — and why?
Standards alignment
No external standards are linked to this topic.