Collinearity of Points
Explore the concept of collinearity and learn how to use the area of a triangle formula to determine if three or more points lie on the same straight line.
About This Topic
Explore the concept of collinearity and learn how to use the area of a triangle formula to determine if three or more points lie on the same straight line.
Key Questions
- Explain the condition for three points to be collinear using the concept of the area of a triangle.
- Compare the method of using the area formula to check for collinearity with the method using the distance formula.
- Justify why three points forming a triangle with zero area must lie on a single straight line.
Active Learning Ideas
See all activities→Activities & Teaching Strategies
See all activities
Planning templates for Mathematics
5E Model
The 5E Model structures lessons through five phases (Engage, Explore, Explain, Elaborate, and Evaluate), guiding students from curiosity to deep understanding through inquiry-based learning.
Unit PlannerMath Unit
Plan a multi-week math unit with conceptual coherence: from building number sense and procedural fluency to applying skills in context and developing mathematical reasoning across a connected sequence of lessons.
RubricMath Rubric
Build a math rubric that assesses problem-solving, mathematical reasoning, and communication alongside procedural accuracy, giving students feedback on how they think, not just whether they got the right answer.
More in Coordinate Geometry
Revisiting the Cartesian Plane
Refresh your understanding of the coordinate plane, including axes, origin, quadrants, and how to plot points using their coordinates.
8 methodologies
The Distance Formula
Learn how to derive and apply the distance formula to calculate the straight-line distance between any two points on the Cartesian plane.
8 methodologies
Applications of the Distance Formula
Use the distance formula as a tool to classify different geometric shapes, such as triangles and quadrilaterals, based on their side lengths.
8 methodologies
The Section Formula
Discover the section formula, which helps find the coordinates of a point that divides a line segment joining two points internally in a specific ratio.
8 methodologies
The Mid-Point Formula
Learn the mid-point formula, a special and simplified case of the section formula, used to find the exact centre of a line segment.
8 methodologies
Area of a Triangle
Learn the formula to calculate the area of a triangle when the coordinates of its three vertices are known.
8 methodologies