## Parts of a Circle

In this tutorial students will learn about the characteristics of a circle. The students will be introduced to the following vocabulary words: chord, diameter, radius, center, circumference and pi. Lastly, the students will be introduced to their relationships between these characteristics.

A **circle** is a set of points that are equidistant from a specific point called the **center**. A circle is named by its center.

A **chord** is a line segment that connects 2 points on the circle.

A **diameter** is a special **chord** that goes through the center of the circle and connects 2 points on the circle.

A **radius** is a line segment that connects with the center and a point on the circle.

**Circumference** is the **distance** around a circle.

## Relationships

diameter = 2 * radius

radius = diameter/2 or (1/2)*diameter

circumference ≈ 3 * diameter

circumference / diameter ≈ 3 or 22/7

π = circumference / diameter

π = 3.1415926…

π is an irrational number

## Fun Fact

The **circumference** *divided* by the **diameter** will **ALWAYS** equal **pi**, **3.1415926…**

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