<P> Of all triangles contained in a given convex polygon, there exists a triangle with maximal area whose vertices are all vertices of the given polygon . </P> <P> One way to identify locations of points in (or outside) a triangle is to place the triangle in an arbitrary location and orientation in the Cartesian plane, and to use Cartesian coordinates . While convenient for many purposes, this approach has the disadvantage of all points' coordinate values being dependent on the arbitrary placement in the plane . </P> <P> Two systems avoid that feature, so that the coordinates of a point are not affected by moving the triangle, rotating it, or reflecting it as in a mirror, any of which give a congruent triangle, or even by rescaling it to give a similar triangle: </P> <Ul> <Li> Trilinear coordinates specify the relative distances of a point from the sides, so that coordinates x: y: z (\ displaystyle x: y: z) indicate that the ratio of the distance of the point from the first side to its distance from the second side is x: y (\ displaystyle x: y), etc . </Li> <Li> Barycentric coordinates of the form α: β: γ (\ displaystyle \ alpha: \ beta: \ gamma) specify the point's location by the relative weights that would have to be put on the three vertices in order to balance the otherwise weightless triangle on the given point . </Li> </Ul>

Which of the following correctly names a side of the triangle below