Mathematics·Geometry·procedural
Angles in triangles (age 10+)
Find unknown angles in triangles, quadrilaterals, and regular polygons using angle sum properties
Suggested ages 10–11
Learning journey
Your child is developing advanced spatial skills — working with 3D shapes and nets, using coordinate grids with negative numbers, calculating angles, and understanding geometric transformations like reflection and translation.
Evidence of understanding
- Find a missing angle in a triangle given two angles (using angle sum = 180°)
- Calculate a missing angle in a quadrilateral (angle sum = 360°)
- Calculate the interior angle of a regular hexagon from the angle sum formula
Assessment prompt
If Angles in triangles (age 10+) knows that angles in a triangle always add up to 180°, and two angles in a triangle are 55° and 70°, can they work out the third angle without measuring it?
Standards alignment
No external standards are linked to this topic.