Here’s a site that goes through the details in a simple way of solving the circumference of a circle @ Math.com
Learn angle amounts with the game Angler @ the website MyMaths.co.uk
Learn and practice using the formula to find the area of a circle @ MathGoodies.com
The History of Pi @ 3.14ever.
Interesting lesson plans in teaching what Pi is @ MiddleWeb.com
How to memorize the numbers in Pi @ Jeff’s Pi
March 14 is Pi Day!
A master site to find Pi websites @ ethemes