Unit 3 · Geometry and Measurement · Lesson One
Types of Angles and the Relationships between them
A complete, illustrated walk-through of the lesson: the concept of an angle, how angles are measured, every angle type, and the relations that connect two angles — followed by exercises and learning games.
Learning Outcomes
- Learn the concept of an angle and its measuring units.
- Identify different types of angles and how to distinguish between them.
- Identify adjacent angles.
- Learn complementary angles.
- Learn supplementary angles.
Key Vocabulary
Straight AngleReflex AngleAdjacent AnglesComplementary AnglesSupplementary Angles
Each term is defined on its own page with a figure you can compare against the printed lesson.
Lesson Map
01
Concept & Types of Angles
Vertex, sides, degrees, minutes and seconds — then the six angle types from zero to reflex.
02Relations between Angles
Adjacent, complementary and supplementary angles, plus the outer-sides rules.
03Worked Examples
Eight solved examples with full steps, including ratios and angle bisectors.
04Activities & Games
Classify-the-angle game, complement/supplement speed drill, protractor challenge and an exam quiz.