By: Tim Lehman

Perimeter and circumference are not difficult
mathematical concepts. Of course, the definitions of **perimeter**
and **circumference**
are important. Students need to get the idea that it is the distance
around an object. (It's how far an ant would walk around the boundary,
or how much fence it would take to build around the shape.) For
a GSP exercise, **click here**.

One of the important ideas that should not be missed this lesson is the meaning of pi. To many, it is some magical number that never repeats, never ends, is 3.14..., and is represents by a wierd symbol.

Students need to know what pi really means.
Do they realize at one time they were all "pi" feet
tall? One possible exercise is for students to measure round objects
and look for relationships between their diameter and circumference.
For more accuracy, GSP could be used. The amount of information
given the students should be altered depending on the time available.
**Click here** for a GSP sketch on
what students will hopefully realize.

Definition links lead to Intermath website dictionary.