Mathematics
Geometry
Procedural
10–11 yrs
Understanding angles (age 10+)
理解角度（10岁以上）
Description
Recognise angles where they meet at a point, are on a straight line, or are vertically opposite; find missing angles using these properties
Mastery Evidence
- Find a missing angle at a point given the other angles (total 360°)
- Use the straight-line property (angles sum to 180°) to find an unknown angle
- Identify vertically opposite angles and use the property that they are equal to find unknowns
Assessment Prompt
If two straight lines cross each other, can your child tell you which pairs of angles are equal (vertically opposite) — and find a missing angle if you give them one of the others?
