Answer:
See explanation
Step-by-step explanation:
A. Prove that angles 1 and 3 are vertical.
1. - linear pair of angles
2. - linear pair of angles are supplementary
3. - linear pair of angles
4. - linear pair of angles are supplementary
5. - substitution property of equality
6. - subtraction property of equality
7. - definition of congruent angles.
So, any two vertical angles are congruent.
B. Prove that angle 3 and angle 5 are congruent.
1. - Corresponding Angles Postulate
2. - definition of congruent angles
3. - vertical angles
4. - definition of congruent angles
5. - substitution property of equality
6. - definition of congruent angles
So, alternate interior angles are congruent
C. Prove that angle 1 and angle 7 are congruent.
1. - Corresponding Angles Postulate
2. - definition of congruent angles
3. - vertical angles
4. - definition of congruent angles
5. - substitution property of equality
6. - definition of congruent angles
So, alternate exterior angles are congruent