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Lesson Materials

What is the relationship between the circumference and the diameter?

READ the instructions on the right and INTERACT with the GeoGebra applet below.


Sorry, the GeoGebra Applet could not be started. Please install Java 1.4 (or later) to use this page.

Objective

6.12 The student will
a. solve problems involving the circumference and/or area of a circle when given the diameter or radius
b. derive approximations for pi (∏) from measurements for circumference and diameter, using concrete materials or computer models.

 Directions Close 
    Move the black point to roll the circle.
  1. Notice the change in length of AD.
  2. Watch the change in the ratio AD:AN.
  3. Does the value of AN change?
  4. Explain the relationship between AD and AN.
 Directions 2 Close 
    Change the diameter.
  1. Move the black point to roll the circle.
  2. Watch the change in the ratio AD:AN.
  3. Does the value of AN change?
  4. Explain the relationship between AD and AN.

 Hands-On Activities Close 
 Other Web Sites Close 
  1. LearnAlberta

Choose Circumference topic under Shape and Space

 Puzzles & Problems tangram Close 
Where did the word pi come from, and how was it determined that the value is approximately 3.14?