Wolfram Demonstrations Projecthttp://demonstrations.wolfram.com/An Open Resource of Interactive Mathematica VisualizationsCopyright 2009 Wolfram Demonstrations Project & ContributorsAngle and Length Measurement of a Polygonhttp://demonstrations.wolfram.com/AngleAndLengthMeasurementOfAPolygon/]]>http://demonstrations.wolfram.com/AngleAndLengthMeasurementOfAPolygon/The Interior Angles of a Triangle Sum to Pihttp://demonstrations.wolfram.com/TheInteriorAnglesOfATriangleSumToPi/]]>http://demonstrations.wolfram.com/TheInteriorAnglesOfATriangleSumToPi/The Medians of a Triangle Divide It into Three Smaller Triangles of Equal Areahttp://demonstrations.wolfram.com/TheMediansOfATriangleDivideItIntoThreeSmallerTrianglesOfEqua/]]>http://demonstrations.wolfram.com/TheMediansOfATriangleDivideItIntoThreeSmallerTrianglesOfEqua/The Medians of a Triangle Are Concurrent: A Visual Proofhttp://demonstrations.wolfram.com/TheMediansOfATriangleAreConcurrentAVisualProof/]]>http://demonstrations.wolfram.com/TheMediansOfATriangleAreConcurrentAVisualProof/The Centroid of a Triangle Divides Each Median in the Ratio 1:2http://demonstrations.wolfram.com/TheCentroidOfATriangleDividesEachMedianInTheRatio12/]]>http://demonstrations.wolfram.com/TheCentroidOfATriangleDividesEachMedianInTheRatio12/Euclid, Book 3, Proposition 22http://demonstrations.wolfram.com/EuclidBook3Proposition22/]]>http://demonstrations.wolfram.com/EuclidBook3Proposition22/The Sum of the Interior Angles of a Triangle Equals 180 Degrees by Paper Foldinghttp://demonstrations.wolfram.com/TheSumOfTheInteriorAnglesOfATriangleEquals180DegreesByPaperF/]]>http://demonstrations.wolfram.com/TheSumOfTheInteriorAnglesOfATriangleEquals180DegreesByPaperF/Interior Angles of a Trianglehttp://demonstrations.wolfram.com/InteriorAnglesOfATriangle/]]>http://demonstrations.wolfram.com/InteriorAnglesOfATriangle/Medial Division of Triangleshttp://demonstrations.wolfram.com/MedialDivisionOfTriangles/]]>http://demonstrations.wolfram.com/MedialDivisionOfTriangles/The Erdös-Mordell Inequalityhttp://demonstrations.wolfram.com/TheErdoesMordellInequality/]]>http://demonstrations.wolfram.com/TheErdoesMordellInequality/Halving a Trianglehttp://demonstrations.wolfram.com/HalvingATriangle/]]>http://demonstrations.wolfram.com/HalvingATriangle/Angles in a Quadrilateral Total 360°http://demonstrations.wolfram.com/AnglesInAQuadrilateralTotal360/]]>http://demonstrations.wolfram.com/AnglesInAQuadrilateralTotal360/Angles in a Triangle Total 180 Degreeshttp://demonstrations.wolfram.com/AnglesInATriangleTotal180Degrees/]]>http://demonstrations.wolfram.com/AnglesInATriangleTotal180Degrees/Oriented Triangle Angleshttp://demonstrations.wolfram.com/OrientedTriangleAngles/]]>http://demonstrations.wolfram.com/OrientedTriangleAngles/The Triangle Inequalityhttp://demonstrations.wolfram.com/TheTriangleInequality/]]>http://demonstrations.wolfram.com/TheTriangleInequality/