# 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.

### Objectives

To understand sum of angles of a quadrilateral is 360°

### Estimated Time

40 minutes.

### Prerequisites/Instructions, prior preparations, if any

- The students should have the knowledge of constructing quadrilaterals.
- 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 :http://mathematicsvillage.blogspot.in/search/label/Activity

### Process (How to do the activity)

- Draw a Quadrilateral ABCD on colour chart Sheet .
- Cut such four Quadrilaterals on four different sheets.
- Mark <A as <1 , <B as <2 , <C as <3 and <D as <4 on each quadrilateral as shown in fig .
- Arrange all four angles of quadrilateral one from each colour at one point.
- What you observe ?
- It forms a complete angle i.e 360 degrees.
- This shows that sum of all angles of quadrilateral is 360 degrees.

- Developmental Questions:

- What is a quadrilateral ?
- How many angles does a quadrilateral have ?
- What is the sum of 4 angles of the quadrilateral according to your findings.

- Evaluation:

- What would be the sum of opposite angles of a quadrilateral ?

- Question Corner:

- What can you say about the four angles in a regular quadrilateral ? Give an example for regular quadrilateral.
- Try proving this property in case of concave quadrilaterals as well.