# Ch 39: 6th-8th Grade Geometry: Circles

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### About This Chapter

## 6th-8th Grade Geometry: Circles - Chapter Summary

For any middle school student who needs reinforcement or clarification about geometry concepts related to circles, the lessons in this chapter have been created to do just that. They'll learn what constitutes a circle and how to calculate the essential dimensions of this shape, including diameter and radius.

Additionally, they'll work through word problems that challenge them to solve problems using circle geometry. Dimensions of quarter circles will also be reviewed. Subject matter experts are available to answer any questions about the material. Short quizzes following each lesson and a chapter exam are available for self-assessment.

## Chapter Lessons and Objectives

Lesson | Objective |
---|---|

Parts of a Circle | Identify parts of a circle such as the center, radius, chords and diameter. |

Central and Inscribed Angles: Definitions and Examples | Define central and inscribed angles. |

How to Find the Radius of a Circle: Definition & Formula | Discover how to find the radius of a circle using a short formula. |

How to Find the Diameter of a Circle: Definition, Formula & Example | See how to find a circle's diameter through example problems. |

Circles: Area and Circumference | Learn and apply formulas to calculate area and circumference of circles. |

Semicircle: Definition, Perimeter & Area Formulas | Demonstrate how to calculate area, perimeter, radius and diameter of semicircles. |

Quarter Circles: Calculating Area, Perimeter & Radius | Explain and use formulas for calculating area, perimeter and radius of quarter circles. |

Circles in Word Problems | Solve word problems involving circles. |

### 1. Parts of a Circle

After watching this video lesson, you will be able to identify the parts of a circle. You will learn the names of four different parts of a circle along with what each part does for the circle.

### 2. Central and Inscribed Angles: Definitions and Examples

When we're working with circles, there are two key angles to know: central angles and inscribed angles. These angles have a few special theorems, which we'll discuss and practice using in this lesson.

### 3. How to Find the Radius of a Circle: Definition & Formula

In this lesson, you will discover the definition of a radius. You will also learn how to find the radius of a circle using three different formulas based on diameter, circumference, and area.

### 4. How to Find the Diameter of a Circle: Definition, Formula & Example

Learn the definition of the diameter of a circle and how to find it using a simple formula. See some examples, then test your knowledge with a short quiz.

### 5. Circles: Area and Circumference

Understanding how to calculate the area and circumference of circles plays a vital role in some of our everyday functions. They serve as the foundation for operating with three-dimensional figures. Learn more about the area and circumference of circles in this lesson.

### 6. Semicircle: Definition, Perimeter & Area Formulas

In this lesson, you'll discover what a semicircle is. You'll also discover the formulas for perimeter and area that will work on every semicircle. Then, test your new knowledge with a brief quiz.

### 7. Quarter Circles: Calculating Area, Perimeter & Radius

Watch as we solve problems involving the quarter circle in this video lesson. Learn what quarter circles look like, how to find their area, their perimeter, and their radius.

### 8. Circles in Word Problems

Watch this video lesson to learn how you can solve word problems that involve circles. Learn how the properties of circles make your problem-solving life that much easier and quicker.

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### Other Chapters

Other chapters within the 6th-8th Grade Math: Practice & Review course

- 6th-8th Grade Math: Basic Arithmetic Operations
- 6th-8th Grade Math: Divisibility
- 6th-8th Grade Math: Properties of Numbers
- 6th-8th Grade Math: Number Theory
- 6th-8th Grade Math: Factoring
- 6th-8th Grade Math: Estimating & Rounding
- 6th-8th Grade Math: Whole Numbers
- 6th-8th Grade Math: Simplifying Whole Number Expressions
- 6th-8th Grade Math: Negative Numbers
- 6th-8th Grade Math: Absolute Value
- 6th-8th Grade Math: Integers
- 6th-8th Grade Math: Rational Numbers
- 6th-8th Grade Math: Inequalities
- 6th-8th Grade Math: Introduction to Decimals
- 6th-8th Grade Math: Operations with Decimals
- 6th-8th Grade Math: Introduction to Fractions
- 6th-8th Grade Math: Operations with Fractions
- 6th-8th Grade Math: Percents
- 6th-8th Grade Math: Exponents & Exponential Expressions
- 6th-8th Grade Math: Roots & Radical Expressions
- 6th-8th Grade Algebra: Writing Algebraic Expressions
- 6th-8th Grade Algebra: Basic Algebraic Expressions
- 6th-8th Grade Algebra: Algebraic Distribution
- 6th-8th Grade Algebra: Writing & Solving One-Step Equations
- 6th-8th Grade Algebra: Writing & Solving Two-Step Equations
- 6th-8th Grade Algebra: Simplifying & Solving Rational Expressions
- 6th-8th Grade Math: The Coordinate Graph
- 6th-8th Grade Algebra: Linear Equations
- 6th-8th Grade Algebra: Systems of Linear Equations
- 6th-8th Grade Math: Properties of Functions
- 6th-8th Grade Math: Graphing Functions
- 6th-8th Grade Math: Solving Math Word Problems
- 6th-8th Grade Measurement: Perimeter & Area
- 6th-8th Grade Geometry: Introduction to Geometric Figures
- 6th-8th Grade Geometry: Angles
- 6th-8th Grade Measurement: Units of Measurement
- 6th-8th Grade Geometry: Triangles
- 6th-8th Grade Geometry: Quadrilaterals
- 6th-8th Grade Geometry: Circular Arcs & Measurement
- 6th-8th Grade Geometry: Polyhedrons & Geometric Solids
- 6th-8th Grade Geometry: Symmetry, Similarity & Congruence
- 6th-8th Grade Geometry: Transformations
- 6th-8th Grade Geometry: Triangle Theorems & Proofs
- 6th-8th Grade Geometry: Similar Polygons
- 6th-8th Grade Geometry: The Pythagorean Theorem
- 6th-8th Grade Math: Data & Graphs
- 6th-8th Grade Math: Probability
- 6th-8th Grade Math: Statistics
- 6th-8th Grade Math: Rates, Ratios & Proportions
- 6th-8th Grade Math: Money
- 6th-8th Grade Math: Consumer Math
- 6th-8th Grade Math: Number Sequences
- 6th-8th Grade Math: Sets
- 6th-8th Grade Algebra: Monomials & Polynomials