# Circle as a shape

From Karnataka Open Educational Resources

A circle is the set of all points in the plane that are a fixed distance from a fixed point.

### Objectives

Understanding circle as a shape

### Estimated Time

30 minutes

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

Prior knowledge of point, lines, angles, polygons

### Materials/ Resources needed

- Digital : Computer, geogebra application, projector.
- Non digital : Worksheet and pencil
- Geogebra files : Introduction to circles.ggb

Download this geogebra file from this link.

### Process (How to do the activity)

- Draw circle with ‘circle with center and point’ or use the slider
- What do you notice, how is the circle formed.
- Which point is the centre of the circle ?
- Plotting points on the circle, connect these points to the centre of the circle.
- What can you say about the segment lengths?
- Measure the segment lengths to show they are equal.
- Establish center of the circle’ and ‘radius’
- Differentiate between circle and region enclosed by a circle.

**Evaluation:**

- By what parameter is the size of a circle defined ?
- Bigger the radius, _____________
- How do you name a circle ?
- Can you draw a circle without knowing the radius ?