Cercle et disque - CE5 - CM2

Understanding the Circle and Disk

Introduction to Concepts

• Professor Yassir introduces the lesson, focusing on understanding the difference between a circle and a disk. He emphasizes the goal of enhancing intelligence through this lesson.

Definitions and Differences

• The circle is defined as the curved line that forms the outer boundary of a round piece of paper, while the disk refers to the surface area enclosed within that boundary.

• In summary, a circle represents the outer edge, whereas a disk encompasses everything inside that edge.

Key Components of a Circle

• To draw a circle, one needs:

• A center point (denoted as E).

• A radius, which is the distance from the center to any point on the circle.

• A diameter, which measures the distance across two points on the circle passing through its center.

Relationships Between Radius and Diameter

• The diameter is twice as long as the radius.

• To find diameter: multiply radius by 2.

• To find radius: divide diameter by 2.

Additional Terminology