Circle Area Inquiry Activity and Worksheets - Discovering Pi with Radius Squared

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  1. This bundle contains two guided inquiry lessons to help students discover pi by:measuring circle circumference and diameter, andmeasuring the area of a circle and the area of the square formed by its radius
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Investigate the formula for calculating the area of a circle using cereal O’s to measure everyday circular objects. This full lesson plan begins with a guided inquiry and then has students work in groups to investigate the relationship between a circle’s area and the area of a square with sides the length of the radius. In a class discussion, you’ll calculate pi by averaging the ratios of everyone’s measurements. Reflection and extension ideas are included.

This activity can either be an introduction to the formula for finding the area of a circle, or it can be used to help students develop a deeper understanding of the formula after they’ve learned it.

Prior to beginning this activity, students should know vocabulary for the basic parts of a circle, including circumference, center, diameter, and radius. They should be very familiar with the concept of area, understand that the area of a square is equal to the square of its sides, and have experience subdividing polygons into rectangles and triangles to develop formulas for area.

A full, free preview is available above to help you decide if this activity will be a good fit for your classroom.

This download is one pdf file that includes:

★Teacher Notes and scripted Lesson Plan

★2 Focus Questions pages

★3 Guided Investigation student pages

★Investigation Instructions Poster

★Blank Class Data Chart

★2 Extra Practice pages with answer keys

★1,000 Digits of Pi Poster

★Investigation Photos page

★My unique Collaborative License, which grants you permission to share printed copies only of this resource with up to four other members of your regular teaching team! (If you’d like to share the digital file, please return to your My Purchases page to purchase additional licenses. See my current Terms of Use for more information.)

Standards Addressed:

CCSS 7.G.B.4


VA SOL 6.10b (2009)

VA SOL 6.7 a,b (2016)

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Distance learning: If needed, you may email the pdf to the parents and students you directly serve, as explained in my updated Terms of Use (2020).


You might also like:

Measuring Circle Circumference and Diameter to Discover Pi

More Geometry Resources

More Inquiry Resources

More Measurement Resources

More Virginia SOL Aligned Resources

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Total Pages
15 + answer keys
Answer Key
Teaching Duration
90 minutes
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to see state-specific standards (only available in the US).
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.


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