Angle sum property of a quadrilateral

From Karnataka Open Educational Resources

Showing the sum of angles of a quadrilaterals by placing the angles of the quadrilateral adjacent to each other with a hand on activity.


To understand sum of angles of a quadrilateral is 360°

Estimated Time

40 minutes.

Prerequisites/Instructions, prior preparations, if any

  1. The students should have the knowledge of constructing quadrilaterals.
  2. They should have the skill of drawing and measuring angles.

Materials/ Resources needed

colour papers, scale , compass, pencil and scissors.

This activity has been taken from the website :


Process (How to do the activity)

  1. Draw a Quadrilateral ABCD on colour chart Sheet .
  2. Cut such four Quadrilaterals on four different sheets.
  3. Mark <A as <1 , <B as <2 , <C as <3 and <D as <4 on each quadrilateral as shown in fig .
  4. Arrange all four angles of quadrilateral one from each colour at one point.
  5. What you observe ?
  6. It forms a complete angle i.e 360 degrees.
  7. This shows that sum of all angles of quadrilateral is 360 degrees.
  • Developmental Questions:
  1. What is a quadrilateral ?
  2. How many angles does a quadrilateral have ?
  3. What is the sum of 4 angles of the quadrilateral according to your findings.
  • Evaluation:
  1. What would be the sum of opposite angles of a quadrilateral ?
  • Question Corner:
  1. What can you say about the four angles in a regular quadrilateral ? Give an example for regular quadrilateral.
  2. Try proving this property in case of concave quadrilaterals as well.