Types of triangles based on angles

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A triangle can be drawn with different measures of angles which also determine the kind of triangle formed.


Recognize the triangles based on the measures of the sides

Estimated Time

20 minutes

Prerequisites/Instructions, prior preparations, if any

Prior knowledge of point, lines, angles, elements of triangle

Materials/ Resources needed

Download this geogebra file from this link.

Process (How to do the activity)

  • Identify the angle types in the triangle.
  • Can the angles in the triangle be of different type – obtuse or right angle.
  • Establish the types of triangles based on the types of angles that form the triangle – when all angles are acute angles, when one of the angle is a right angle and when one of the angle is obtuse angle.
  • Is it possible to have a triangle with two right angle or two obtuse angle. Why or why not?
  • What kind of a triangle is formed when all the angles are equal? For what measure of the angle such a triangle is formed?
  • Can a triangle be formed with a reflex angle.
  • Measure the angles for different triangle, recognize the types of angles and conclude the type of triangle.
Observation Angle 1 measure and

its Type

Angle 2 measure and

its Type

Angle 3 measure and

its Type

What can you say about angles? Type of triangle formed
Triangle 1
Triangle 2
Triangle 3

Evaluation at the end of the activity

  • Are children able to recognize the types of triangles based on the angles in a triangle.