Wahidah, Riva AtulMashadiHasriati2012-10-152012-10-152012-10-14Rangga Dwijunanda Putrahttp://hdl.handle.net/123456789/177We discuss prove the Erdős-Mordell Inequality. We will use signed distances from the sides of a triangle to prove that Erdős-Mordell Inequality not only to interior point of triangle, but also to exterior point of triangle. Here we detail a method proposed by Dergiades, N. Forum Geom. 4: 67–68 (2004).otherErdős-Mordell InequalitySigned DistancesInterior Point of TriangleArticle