The only statements that must be true are ones that describe the markings on the diagram:
NO as an angle bisector
N is the vertex of a pair of congruent angles
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The only other fact that must be true is that segments on the left side of the diagram are proportional to those (corresponding) on the right. (This is a property of the angle bisector.) There is nothing that says the sides must be equal, or that the triangle is isosceles.
