How Do You Find the Circumference of a Circle if You Know the Radius?

How Do You Find the Circumference of a Circle if You Know the Radius?

Note:

Trying to find the circumference of a circle? Know the radius? Then you can use the formula for the circumference of a circle to get the answer! Just plug the value for the radius into the formula and solve. This tutorial shows you how!

Keywords:

  • circle
  • find circumference
  • radius
  • pi
  • multiply
  • solve for circumference

Background Tutorials

  • Fluently add, subtract, multiply, and divide multi-digit decimals using the standard algorithm for each operation.

      • How Do You Multiply Decimals?How Do You Multiply Decimals?

      How Do You Multiply Decimals?

      Doing math with paper and pencil can come in real handy, so make sure you're comfortable multiplying decimals by hand. After all, you don't want the calculator to be a crutch!

  • Evaluate expressions at specific values of their variables. Include expressions that arise from formulas used in real-world problems. Perform arithmetic operations, including those involving whole-number exponents, in the conventional order when there are no parentheses to specify a particular order (Order of Operations).

      • How Do You Evaluate an Algebraic Expression?How Do You Evaluate an Algebraic Expression?

      How Do You Evaluate an Algebraic Expression?

      Plugging variables into an expression is essential for solving many algebra problems. See how to plug in variable values by watching this tutorial.

      • What is a Variable?What is a Variable?

      What is a Variable?

      You can't do algebra without working with variables, but variables can be confusing. If you've ever wondered what variables are, then this tutorial is for you!

  • Know the formulas for the area and circumference of a circle and use them to solve problems; give an informal derivation of the relationship between the circumference and area of a circle.

      • What is a Circle?What is a Circle?

      What is a Circle?

      Circles are a fundamental part of math! In this tutorial, you'll be introduced to circles and see the different parts of a circle such as the diameter, radius, and chord. Check out this tutorial to learn about circles!

      • What is Circumference?What is Circumference?

      What is Circumference?

      The circumference of a circle is the distance around that circle. But what is the formula to find the circumference? In this tutorial, you'll learn the formulas for the circumference of a circle. Take a look!

Further Exploration

  • Know the formulas for the area and circumference of a circle and use them to solve problems; give an informal derivation of the relationship between the circumference and area of a circle.