Know the Parts of a Circle

In this activity, we will be learning to identify the parts of a circle. 

A circle can be drawn using a pair of compasses.

In the diagram below, the distance set between the point and the pencil tip is called the radius.

The point marks the centre of the circle.

The distance straight across from one edge to the other, going through the centre, is called the diameter.

The diameter is twice as long as the radius.

The radius is half the length of the diameter.

When we draw a circle, the pencil line around the perimeter is called the circumference.

It is a curved line.

Let's try an example question together.

Example

What is the perimeter of a circle called?

Answer

We know that the perimeter is the outside edge or edges of a shape.

The perimeter of a circle is called the circumference. 

Does that all make sense?

Now it's time to try some questions about parts of circles. 

Good luck!