Centroid of a triangle

As performed in real lab:

Materials required:

Coloured paper, pencil, a pair of scissors, gum.


  1. From a sheet of paper, cut out three types of triangle: acute-angled triangle, right-angled triangle and obtuse-angle triangle.
  2. For an acute-angled triangle, find the mid-points of the sides by bringing the corresponding two vertices together. Make three folds such that each Joins a vertex to the mid-point of the opposite side. [Fig (a)]
  3. Repeat the same activity for a right-angled triangle and an obtuse-angled triangle. [Fig (b) and Fig (c)]

          Acute-angled(a)                  Right-angled(b)                             Obtuse-angled(c)

As performed in the simulator:

  1. Create a triangle ABC by providing three points A, B and C over the workbench.
  2. Draw the mid-points of each line segment.
  3. Click on each mid-points to draw their respective bisector lines.
  4. You can see, Centroid lies inside the triangle for all acute angled, obtuse angled & right angled triangle.


  • The students observe that the three medians of a triangle concur.
  • They also observe that the centroid of an acute, obtuse or right angled triangle always lies inside the triangle.