**About the
Circles Introduction
Lesson**

**Summary**

This is an introductory lesson about circles.

**Objectives**

• to define and explain the concept of a circle;

•
to identify the different parts of a circle;

•
to explain the relation between the radius and diameter of a circle;

•
to teach students how to solve simple problems involving radius and diameter.

**Suggested Grades**

4th Grade

5th Grade

6th Grade

**Excerpt **

*
The idea of a circle, the basis for the wheel, has been known since the beginning of recorded history. Early scientists thought that there was something perfect or divine about circles.*

In modern times, we generally refer to a circle as a simple shape of geometry. It consists of points in a plane that are all the same distance from a given point. The given point of a circle is called the center. The perimeter of a circle is known as the circumference of a circle. We can see how these three terms apply to a circle by looking at the picture below.

The distance from the center of a circle to any point along the circumference of a circle is called the radius. The diameter of a circle is a line whose endpoints touch the circumference of a circle. This line must also pass through the center of the circle.

*Continued...*