A GM_Triangle is a planar GM_Polygon defined by 3 corners; that is, a GM_Triangle would be the result of a constructor of the form:<br/>GM_Polygon(GM_LineString(#lt;P1, P2, P3, P1#gt;))<br/><br/>where P1, P2, and P3 are three GM_Positions. GM_Triangles have no holes. GM_Triangle shall be used to construct GM_TriangulatedSurfaces. <br/><br/>NOTE The points in a triangle can be located in terms of their corner points by defining a set of barycentric coordinates, three nonnegative numbers c1, c2, and c3 such that c1+ c2 + c3 = 1.0. Then, each point P in the triangle can be expressed for some set of barycentric coordinates as:<br/>