## What is a circle?

A circle is a **2D curved shape**, every point of which is the same distance from a fixed point in the centre.

**When do children learn about circles in primary school?**

Children begin learning about 2D shapes in **Year 1**, where they learn to **recognise and name circles**, triangles, squares and rectangles.

They may also discuss the properties of different shapes, for example the fact that circles have curved sides and triangles have straight sides.

In **Year 2**, children start to **look at 3D shapes and will be asked to recognise 2D shapes on these**. For example, they will be asked to say how many circular faces they can see on a cylinder (there are two):

At the end of KS2, in Year 6, children will be asked to **illustrate and name parts of circles, including radius, diameter and circumference.**

### What is the circumference of a circle?

The **circumference** is **the** **measurement all the way around the outside edge of a circle**.

### What is the radius of a circle?

The **radius** is the **distance from the centre of the circle to the edge of the circle.**

### What is the diameter of a circle?

The **diameter** is **the straight line going through the centre of a circle, connecting two points on the circumference**.

Y6 children may be given various circles and asked to measure their circumference (using string), radius and diameter.

They will learn that **the diameter of a circle is twice the radius** and may be introduced to the **formulae** to help them calculate the circumference of a circle (2 x π x r) and the area of a circle (π x r²).