Mathematics
Geometry
Conceptual
9–10 yrs
Regular and irregular polygons
正多边形与不规则多边形
Description
Distinguish between regular and irregular polygons based on reasoning about equal sides and equal angles
Mastery Evidence
- 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 your child a stop sign (regular octagon) and a wonky eight-sided shape, can they explain which is regular and which is irregular — and why?
