Ontario · Grade 8
G8.E2.2
Grade 8 — Solve problems involving the angle properties of intersecting lines, parallel lines cut by a transversal, and polygons.
Grade 8 — Solve problems involving the angle properties of polygons, where the 180° angle sum of a triangle is applied.
A note on this mapping: Ontario has no expectation that states "the angles of a triangle sum to 180°"; it is used inside the angle-property work of G6.E2.3 and G8.E2.2, so this pairing is a judgement call.
The 2 skills that cover it
What a student should be able to do
- Classify angles as acute, right, obtuse or straight.
- Use complementary and supplementary relationships to find an angle.
- Apply vertical angle and linear pair relationships.
- Find angles formed when a transversal crosses parallel lines.
- Classify triangles by sides and by angles.
- Find a missing angle using the 180-degree angle sum.
- Apply the exterior angle theorem.
- Decide whether three lengths can form a triangle.