Big Ideas Math: Modeling Real Life, Grade 7
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Big Ideas Math: Modeling Real Life, Grade 7 View details
1. Circles and Circumference
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Exercise 5 Page 363

Recall the formula for finding circumference of a circle given its diameter.

28.26 inches

Practice makes perfect

Consider the shape of the pool on a diagram.

Let's find the circumference of the circle. The circumference C of a circle with diameter d is calculated using the formula below. C=π d From the figure, we know that the diameter of the circle is 9 inches. We can substitute 9 for d in the formula and then calculate C. We will use 3.14 as an estimate for π.
C=Ď€ d
C=( 3.14)( 9)
C=28.26
The circumference of the circle is approximately 28.26 inches.

Extra

More About Circles!

Are you interested in learning more about circles? Our Mathleaks original content can teach you all about them! Check out the following resources to see real-world uses for circumference and area, how circles compare to other shapes and why, as well as some higher level topics that you can look forward to learning about in Geometry and Algebra 2.