Final Answer:
The statement TE-TE can be used when proving ASTE - ANTE because TE bisects line segment SN, and according to the Segment Bisector Theorem, it divides the segment into two congruent parts. Therefore, TE = TE, establishing an important equality in the proof.
Step-by-step explanation:
In the given scenario, the line segment TE is a bisector of SN. According to the Segment Bisector Theorem, when a segment is bisected, it divides the segment into two congruent parts. Mathematically, this can be expressed as TE = SE. This property is fundamental in our proof as it provides the basis for the subsequent statements.
Another key aspect is the supplementary nature of Angles 1 and 3. When two angles are supplementary, their measures add up to 180 degrees. In this case, if Angle 1 is congruent to Angle 3, we can express this relationship as m∠1 + m∠3 = 180°. This supplementary property is crucial for establishing relationships between angles in the triangles ASTE and ANTE.
Additionally, the statement "Congruent parts of congruent triangles are congruent (CPCTC)" plays a pivotal role. Once we establish the congruence of corresponding parts of triangles ASTE and ANTE, we can conclude that corresponding angles and sides are also congruent. This principle is a direct application of CPCTC and strengthens our overall proof.
Lastly, the assertion that every segment is congruent to itself is a basic property of equality. In mathematical terms, it is expressed as AB = AB, where AB is any segment. This property helps in reinforcing the equality relationships in the proof, providing a solid foundation for the logical progression of our argument.