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Pi Graph

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    The Exploratorium

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Pi Graph

In this activity, learners use a straight line to learn about circles. Learners measure and record the diameter and circumference of different sized cylindrical objects on a chart. Learners then plot the diameters and circumferences on a graph and calculate the slope to discover the linear relationship between the two proprieties.

Quick Guide

Preparation Time:
Under 5 minutes

Learning Time:
30 to 45 minutes

Estimated Materials Cost:
$1 - $5 per group of students

Age Range:
Ages 11 - 18

Resource Type:


Materials List (per group of students)

  • cylindrical objects of different sizes
  • string
  • ruler
  • graph paper
  • large piece of graph paper to collect group data (optional)


  • Mathematics
    • Algebra
      • Equations and Inequalities
      • Patterns
      • Variables and Expressions
    • Data Analysis and Probability
      • Data Analysis
      • Data Collection
      • Data Representation
    • Geometry
      • Solid Geometry
    • Measurement
      • Units of Measurement
      • Size and Scale
      • Circles
      • Rate
    • Number and Operations
      • Decimals
    • Representation
  • The Nature of Science
    • The Scientific Process
      • Conducting Investigations
      • Gathering Data
      • Formulating Explanations
      • Communicating Results


To use this activity, learners need to:

  • see
  • read
  • touch

Learning styles supported:

  • Involves hands-on or lab activities


This resource is part of:

Access Rights:

  • Free access


  • Yu, Julie


  • All Rights Reserved, Exploratorium, ©2008

Funding Sources:

  • National Science Foundation, 0610238
  • National Science Foundation, 0925383


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