# Circles 1 - Circumference and Area

Taught by YourMathGal
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Lesson Summary:

In this lesson, you'll learn how to calculate the circumference and area of a circle using easy-to-remember formulas. The circumference of a circle is found by doubling the radius and multiplying by pi, while the area is found by squaring the radius and multiplying by pi. You'll also learn how to estimate the values of the circumference and area by using an approximation for pi. By the end of the lesson, you'll have a solid understanding of how to calculate these measurements for circles of any size.

Lesson Description:

Easy formulas and examples for circumference and area of a circle: C = 2r * pi and A = r^2 * pi;

More free YouTube videos by Julie Harland are organized at http://yourmathgal.com

• Diameter of a circle - A description and explanation of what the diameter of a circle is and how to calculate other measurements from the diameter.
• Circumference of a circle - Definition of circumference of a circle, how to find it, and some interesting facts about circumference.
• Area of a circle - The definition of area of a circle as well as explanations of how to find the area of a circle is shown with several formulas.
• What is the circumference of a circle?
• What is the formula for the circumference of a circle?
• What is the exact circumference of a circle if its radius is 5 feet?
• How can you approximate the circumference of a circle using 3.14 as pi?
• How do you find the area of a circle?
• What is the formula for the area of a circle?
• How do you find the exact area of a circle if its radius is 5 feet?
• How can you approximate the area of a circle using 3.14 as pi?
• How can you remember the formulas for circumference and area of a circle?
• How can you find the exact circumference and area of a circle if r = 3?
• #### Staff Review

• Currently 4.0/5 Stars.
This idea of circumference / distance around / perimeter of a circle is explained in this lesson. An example problem of finding the circumference of circles is shown and explained. This is a good introductory tutorial on finding circumference. Area of a circle is also explained and an example problem is shown.