Answer:
Lines d and e are parallel and lines s and t are also parallel
1. Alternate Exterior Angles Theorem
2. Corresponding Angles Postulate
3. Alternate Angles Postulate
4. Co-interior Angles Theorem
Explanation:
Given the below;
1. Given that;
[tex]\angle1\cong\angle4[/tex]
The theorem that justifies the above is the Alternate Exterior Angles Theorem which states that if a pair of parallel lines are cut by a transversal, then the alternate exterior angles are congruent.
2. Given that;
[tex]\angle2\cong\angle3[/tex]
The theorem that justifies the above is the Corresponding Angles Theorem which states that if a pair of parallel lines are cut by a transversal, then the corresponding angles are congruent.
3. Given that;
[tex]\angle6\cong\angle7[/tex]
The theorem that justifies the above is the Alternate Angles Theorem which states that if a pair of parallel lines are cut by a transversal, then the alternate angles are congruent.
4. Given that;
[tex]m\angle5+m\angle8=180[/tex]
The theorem that justifies the above is the Co-interior Angles Theorem which states that if a pair of parallel lines are cut by a transversal, angles that are in the same similar position are supplementary, that is, they add up to 180 degrees.
