# Introduction to quadrilaterals

From Karnataka Open Educational Resources

This activity explores formation of a quadrilateral and elements related with the shape.

### Objectives

- To make quadrilateral
- Measure sides – segment lengths
- Measure interior angles and find their sum
- Measure length of diagonals and angle between diagonals

### Estimated Time

30 minutes

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

Prior knowledge of point, lines, angles, intersecting lines, vertically opposite angles

### Materials/ Resources needed

- Digital : Computer, geogebra application, projector.
- Non digital : worksheet and pencil.
- Geogebra files : 'Introduction to quadrilaterals.ggb'

Download this geogebra file from this link.

### Process (How to do the activity)

- What is a quadrilateral? How many line segments are required for a quadrilateral. What are these line segments called?
- How many vertices in a quadrilateral? How many interior angles ?
- How many lines can be drawn such that they join opposite vertices in a quadrilateral?What are these lines called?
- Do the two lines intersect with each other? At the point of intersection how many angles are formed?Do you notice any equal angles? What kinds of angle pairs are formed at the point of intersection?
- What is the measure of the total angle at the point of intersection of diagonals?

**Evaluation at the end of the activity**

- Can the vertices of a quadrilateral be anywhere on a plane?
- Can the vertices of a quadrilateral lie on a straight line?