Complete the proof. Someone please help me answer this!

Answer:
Step-by-step explanation:
Supplementary angles are two or more angles that add up to give the measure of angle on a straight line (i.e [tex]180^{o}[/tex]).
It can be deduced from the given question that;
1. <1 and <2 are supplementary, also <1 and <3 are supplementary. Reason: as given in the question.
2. Given statements: m<1 + m<2 = [tex]180^{o}[/tex], and m<1 + m<3 = [tex]180^{o}[/tex]. The reason is the definition of supplementary angles.
3. Statement: m<2 = m<3. The reason is a transitive property.
4. Statement: m<1 + m<2 = m<1 + m<3. The reason is subtraction property of equality.
5.Given statement: <2 ≅ <3. The reason is that definition of congruent angles.
Therefore, <2 ≅ <3.