Wolfram Research
Wolfram Math World: Triangle Centroid
This site from MathWorld gives a diagram of a triangle with its centroid labeled. The site details how to find the centroid with links to the key terms. The site details many other interesting properties of the triangle centroid.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Centroid: Center of Gravity
At this site you will find am online discussion about the centroid of a triangle. The page begins with a discussion of observations leading to the centroid of a triangle. Dr. Math explains the correct findings as well as the errors made...