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Art of Problem Solving Animated Proofs Gallery

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The above image illustrates the fact that of all triangles inscribed in a given triangle, the one with least perimeter connects the feet of the given triangle. You can click and drag several of the points in the diagram - try it and see!

Want to learn how to tackle those tough AMC/AIME/Olympiad counting and probability problems? Check out Art of Problem Solving's Intermediate Counting & Probability by David Patrick.