# Circle Proofs Worksheets

Tips When Writing Circle Proofs - Circles are defined as the set of all the points that lie equidistant from a distance r, known as the radius. In geometry, we say that all circles are similar, that means that we can take one circle, alter it to match up with the other one. We take the smaller circle and move it to a point where its center coincides with the bigger circle. Or, we can take the smaller circle, enlarge it until its radius is the same as the bigger circle. Suppose we have to prove that angle subtended at the circumference by a semicircle is a right angle. First, we will create a problem statement. Draw a circle and marks its diameter and center using the diameter of the circle, draw the two sides of the triangle and extend them to meet at the vertex. Next, draw a radius from the vertex to the center and split the triangle. The two triangles will have two sides of the same length, and hence these are the isosceles triangles. Also, these isosceles triangles will have two angles of the same measurements. Lastly, we will add up the angle to find that their sum is equal to 180 degrees.

• ### Basic Lesson

Guides students through Circle Proofs step by step.

• ### Intermediate Lesson

Demonstrates how to complete a circle proof.

• ### Independent Practice 1

A really great activity for allowing students to understand the concepts of the Circle Proofs.

• ### Independent Practice 2

Students determine the Circle Proofs in 20 assorted problems. The answers can be found below.

• ### Homework Worksheet

Students are provided with 12 problems to achieve the concepts of Circle Proofs.

• ### Skill Quiz

This tests the students ability to understand Circle Proofs.

• ### Homework and Quiz Answer Key

Answers for the homework and quiz.

• ### Lesson and Practice Answer Key

Answers for both lessons and both practice sheets.

• ### Basic Lesson

Guides students through segment and arc proofs.

• ### Intermediate Lesson

Demonstrates how to prove angles between two adjacent circles.

• ### Independent Practice 1

A really great activity for allowing students to understand the concepts of the Circle Proofs.

• ### Independent Practice 2

Students use Circle Proofs in 20 assorted problems. The answers can be found below.

• ### Homework Worksheet

Students are provided with 12 problems to achieve the concepts of Circle Proofs.

• ### Skill Quiz

This tests the students ability to understand Circle Proofs.

• ### Homework and Quiz Answer Key

Answers for the homework and quiz.

• ### Lesson and Practice Answer Key

Answers for both lessons and both practice sheets.

#### A Geometry Funny:

Who invented the Round Table?
Sir Cumference.