Basic Proportionality Theorem for a Triangle
Objective
To verify the basic proportionality theorem by using parallel lines board, triangle cut outs.
Basic Proportionality Theorem
If a line is drawn parallel to one side of a triangle, to intersect the other two sides at distinct points, the other two sides are divided in the same ratio.
Prerequisite Knowledge
- Statement of Basic Proportionality theorem.
- Drawing a line parallel to a given line which passes through a given point.
Materials Required
White chart paper, coloured papers, geometry box, sketch pens, fevicol, a pair of scissors, ruled paper sheet (or Parallel line board).
Procedure
- Cut an acute-angled triangle say ABC from a coloured paper.
- Paste the ΔABC on ruled sheet such that the base of the triangle coincides with ruled line.
- Mark two points P and Q on AB and AC such that PQ || BC.
- Using a ruler measure the length of AP, PB, AQ and QC.
- Repeat the same for right-angled triangle and obtuse-angled triangle.
- Now complete the following observation table.
Observation
Result
In each set of triangles, we verified that
Learning Outcome
In all the three triangles the Basic Proportionality theorem is verified.
