Activity Overview
In this activity, students investigate the circumference of circles and learn about the irrational number Pi.
Before the Activity
Start the Geoboard App and format it
See the attached PDF file for detailed instructions for this activity
Print pages 123 - 129 from the attached PDF file for your class
During the Activity
Distribute the page to the class.
Follow the Activity procedures:
Draw a circle with radius = 1/2 and find its perimeter
Draw and measure the diameter of the circle
Similarly draw four circles with radii r = 1, 2, 3, and 4
Calculate the circumference/diameter ratio and check using the formula in the calculator
Observe that the perimeter of the circle is given by 2πr, and the circumference divided by the diameter is always equal to π (3.1416)
Set up a scatter plot with the circumference versus diameter data
Guess the value of m in the equation for the line Y = mX
Graph the predicted value and adjust the value until a line of best fit is obtained
Note that Y = 3.1416X
After the Activity
Review student results:
As a class, discuss questions that appeared to be more challenging
Re-teach concepts as necessary