Proving Properties of Parallel Lines Cut by a Transversal
Supplementary Angles are pairs of angles such that their sum is 180°. Each of these has a theorem that can be used to prove that the two lines are parallel. Theorems on Proving Parallel Lines: Corresponding Angles Theorem. If two parallel lines are cut by a transversal, then the corresponding angles are congruent.
Answer the following questions based on the activity above.
- What pairs of angles are formed when two lines are cut by a transversal?
It consists of Corresponding Angles Theorem, Same Side Interior Angles Theorem, Same Side Exterior Angles Theorem, Alternate Interior Angles Theorem and the Alternate Exterior Angles Theorem.
- What pairs of angles have equal measures? What pairs of angles are supplementary?
Vertical Angles are known to have an equal measures all of the time, whereas the Adjacent Angles are always supplementary.
- Can the measures of any pair of angles (supplementary or equal) guarantee the parallelism of lines?
Yes, it can.
- What have you learned from the lesson?
Alternate Exterior Angles Theorem, If two parallel lines are cut by a transversal, then the alternate exterior angles are congruent.
- How can you apply it to real-life situation/s?
We can use it by familiarizing objects like, some examples of parallel lines cut by a transversal: Zebra crossing on the road. Road and railway crossing. Railway tracks with sleepers.