Study Notes
Polygons are shapes with straight sides. They can have different numbers of sides and angles.
- Triangle — A polygon with three sides and three angles. Example: The sum of interior angles is 180°.
- Quadrilateral — A polygon with four sides and four angles. Example: The sum of interior angles is 360°.
- Hexagon — A polygon with six sides and six angles. Example: The sum of interior angles is 720°.
- Exterior Angle of a Triangle — The exterior angle is equal to the sum of the two opposite interior angles. Example: If one exterior angle is 60°, the sum of the two opposite interior angles is also 60°.
- Sum of Exterior Angles of a Polygon — The sum of exterior angles of any polygon is always 360°. Example: For a hexagon, each exterior angle is 60°.
Exam Tips
Key Definitions to Remember
- Sum of interior angles of a triangle is 180°
- Sum of interior angles of a quadrilateral is 360°
- Sum of interior angles of a hexagon is 720°
- Sum of exterior angles of any polygon is 360°
Common Confusions
- Confusing the sum of interior angles with the sum of exterior angles
- Forgetting that the sum of exterior angles is always 360° regardless of the number of sides
Typical Exam Questions
- What is the sum of the interior angles of a triangle? 180°
- How do you calculate the sum of the interior angles of a quadrilateral? By adding up the angles to get 360°
- What is the exterior angle of a regular hexagon? 60°
What Examiners Usually Test
- Understanding of how to calculate the sum of interior angles
- Ability to apply the exterior angle theorem in triangles
- Knowledge of the sum of exterior angles in polygons