Back To Course

High School World History: Tutoring Solution35 chapters | 452 lessons

Watch short & fun videos
**
Start Your Free Trial Today
**

Start Your Free Trial To Continue Watching

As a member, you'll also get unlimited access to over 70,000 lessons in math, English, science, history, and more. Plus, get practice tests, quizzes, and personalized coaching to help you succeed.

Free 5-day trial
Your next lesson will play in
10 seconds

Lesson Transcript

Instructor:
*Yuanxin (Amy) Yang Alcocer*

Amy has a master's degree in secondary education and has taught math at a public charter high school.

In this video, you'll learn how to define and find the circumference of a circle using two equations: one that involves the diameter and another that involves the radius.

Our earth is a sphere, and if we sliced it in half, we'd end up with a circle. **Circumference** is the distance around a circle. We can measure the circumference of the earth by measuring the distance we'd cover if we walked the way around the world. To understand circumference, we also need to understand the meaning of diameter and radius.

The **diameter** is the distance across the center of a circle, shown in green in this image. The **radius** is the distance from the center to the edge of a circle, shown in red.

There are two ways to write the equation for the circumference.

You can use either of these equations, depending on whether the problem provides you with the diameter or the radius.

There are two ways you can apply the equation for the circumference of a circle using the diameter.

The first is by using the equation to find the circumference given the diameter. For example, if a problem gives you a diameter of 7, you'd plug in the value of the diameter for *d* and replace pi with 3.14.

The second way to use the equation is when you need to find the diameter given a circumference, such as 21.98 inches. To do this, divide both sides by pi.

There are also two ways you can apply the equation for the circumference of a circle using the radius.

The first is by using the equation to find the circumference given the radius of a circle. For example, let's say the problem gives you a radius of 6 inches. You'd plug the 6 into the *r* variable and replace pi with 3.14.

The second way to use the equation is when you're asked to find the radius given a circumference, such as 37.68 inches. Here, you'll rely upon the equation for the circumference using the radius, but this time you'll use algebra to solve the equation for *r*. To do this divide both sides of the equation by 2 and pi.

In this lesson, you learned that **circumference** is the distance around a circle. You also learned that the **diameter** is the distance across the center of a circle and the **radius** is the distance from the center to the edge of a circle. There are two equations you can use to find the circumference of a circle. One involves the diameter and the other involves the radius.

Alternatively, you can also use these equations to find the diameter or radius of a circle when given the circumference.

To unlock this lesson you must be a Study.com Member.

Create
your account

Already a member? Log In

BackDid you know… We have over 95 college courses that prepare you to earn credit by exam that is accepted by over 2,000 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

You are viewing lesson
Lesson
3 in chapter 2 of the course:

Back To Course

High School World History: Tutoring Solution35 chapters | 452 lessons

- What Is Topography and How Is Topography Reshaped? 5:18
- What is a Cubic Foot? - Definition & Formula 5:14
- What is Circumference? - Definition & Equation 2:42
- What is Geography? - Definition, Facts & Types 3:11
- Map Projections: Mercator, Gnomonic & Conic 4:41
- Types of Maps: Population, Topographic, Weather, Political & World Maps 4:22
- Geographic Coordinates: Latitude, Longitude & Elevation 7:19
- US Time Zones: Pacific, Mountain, Central & Eastern 3:45
- Population Distribution: Rural vs. Urban Areas 6:47
- Population Distribution Factors: Job Availability, Quality of Life & Ethnicity 4:43
- Geography and Climate: Effects on Civilizations 7:29
- Factors Involved in Climate Change 10:02
- North Dakota: State History & Facts
- Go to Geography: Tutoring Solution

- Finding & Retaining Talent in an Agile Organization
- Cultural Agility for Organizations
- Psychology 306: Advanced Abnormal Psychology
- Computer Science 108: Introduction to Networking
- Psychology 316: Advanced Social Psychology
- Agile Talent Retention Strategies
- Understanding Cultural Agility in Organizations
- Intro to Agile Organizations
- Barriers to Cultural Agility in the Workplace
- Finding Agile Workers
- Study.com CLEP Scholarship for Military Members
- Study.com Scholarship for Texas Students & Prospective Teachers
- Study.com Scholarship for Florida Students & Prospective Teachers
- What are TExMaT Exams?
- What is the Florida Teacher Certification Examination (FTCE)?
- Study.com TExES Scholarship: Application Form & Information
- Study.com FTCE Scholarship: Application Form & Information

- Challenges in Communicating With Customers Over the Phone
- Teaching Kids How to Count
- Managing Discounts & Plops in Team Meetings
- Forensic Serology: Definitions & Examples
- How to Manage Program-Level Issues
- Surah 55 in the Qur'an: Analysis & Symbolism
- Ethnic Groups in Africa
- What is the Negotiator's Dilemma?
- Quiz & Worksheet - Criminal Insanity Law
- Quiz & Worksheet - Vehicular Homicide & Law
- Quiz & Worksheet - Passive-Aggressiveness on the Job
- Quiz & Assessment - Tolstoy's God Sees the Truth But Waits
- Quiz & Worksheet - Preventing Burnout on Work Teams
- International Law & Global Issues Flashcards
- Foreign Policy, Defense Policy & Government Flashcards

- High School World History: Help and Review
- Common Core ELA Grade 8 - Literature: Standards
- AP Psychology: Exam Prep
- Physical Science: Middle School
- Common Core Math - Geometry: High School Standards
- Praxis Earth & Space Sciences: Minerals and Rocks
- Water Systems
- Quiz & Worksheet - Grabbing the Audience's Attention
- Quiz & Worksheet - Behaviorism in Education
- Quiz & Worksheet - Inductive & Deductive Reasoning Differences
- Quiz & Worksheet - Indochina (1900-1945)
- Quiz & Worksheet - Effects of Substance Use on Health

- State & Non-State Actors in International Politics
- How to Identify Thermal & Radiation Hazards
- How to Improve Reading Comprehension
- How to Prepare for College
- Difference Between DO & MD
- Informational Writing Prompts
- Enlightenment Lesson Plan
- What Is ILTS?
- Script Writing Prompts
- English Conversation Topics
- Sarasota Adult Education
- How to Send SAT Scores to Colleges

Browse by subject