Circle Theorem: Angle at the Center of the Circle Is Twice The Angle at the Circumference

Let's start with a test!

The Test

Here is a -question, multi-choice test for the "Circle Theorem: Angle at the Center of the Circle Is Twice The Angle at the Circumference" lesson. The pass mark is 90%. Don't worry! All the information you need to pass is in the lesson section under the test.

The Lesson

The angle subtended by an arc at the center of a circle is twice the angle subtended by the same arc at the circumference.

How to Use the Circle Theorem where the Angle at the Center Is Twice the Angle at the Circumference

Step-by-Step:

Answer:

The angle at the center of the circle is 80°.

Another Real Example of How to Use the Circle Theorem where the Angle at the Center Is Twice the Angle at the Circumference

In the previous example, the angle at the circumference is given so the angle at the center can be found. In this example, the angle at the center is given so the angle at the circumference can be found.

Step-by-Step:

Answer:

The angle at the circumference of the circle is 50°.

Useful Definitions

An arc is a portion of the circumference. The angle subtended by an arc is the angle made by lines joining the ends of an arc to a point. The angle subtended by an arc at the center of the circle is the angle made by lines joining the ends of the arc to the center of the circle. The angle subtended by an arc at the circumference of the circle is the angle made by lines joining the ends of the arc to any point on the circumference of the circle.

You might also like...