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Unit Plan
Cut the Knot

Cut the Knot!: Polygons: Formality and Intuition

For Students 9th - 10th
This is a very interesting site about polygons. The site begins by distinguishing between shapes whose sides intersect and polygons whose sides do not overlap. After this short introduction, you will find information regarding area and...
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Unit Plan
Cut the Knot

Cut the Knot!: Napoleon's Theorem

For Students 9th - 10th
Site that describes in detail Napoleon's theorem. To understand this site be sure you understand what the centroid of an object is. The site describes polygons in terms of the roots of unity of a function. The page gives an interactive...
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Website
Cut the Knot

Cut the Knot!: Interactive Mathematics: Geometry Articles, Theorems, Problems

For Students 9th - 10th
Contains over five hundred Geometry articles, problems, puzzles, and games. Some sites relating to circles are provided within this list.
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Unit Plan
Cut the Knot

Cut the Knot!: Napoleon's Theorem

For Students 9th - 10th
This site gives an explanation of Napolean's Theorem and gives several links to Napoleon's Theorem.