A postulate and theorems being formulated when a transversal cut the parallel lines. this focuses on the relationship of the three pairs of angles being formed.

1. POSTULATE AND THEOREMS
INVOLVING TRANSVERSAL
Elton John B. Embodo

2. STATEMENT OF THE AIM
Analyze statements about Postulate
and Theorems involving Transversal;
Solve equations involving Postulate
and Theorems involving Transversal;
Prove a given statement by citing
proofs.

3. COPY THE FIGURE DRAWN ON THE BOARD ON YOUR
SHEET OF PAPER, AND DO THE FOLLOWING:
 Use a ruler to copy the figure on your sheet.
 Make sure that line l and line k are properly drawn as
parallel.
 Use a protractor to measure the alternate interior angles:
and , and .
 Measure the alternate exterior angles: and
and .
 Measure also the corresponding angles; and
and , and , and .
 Observe the measure of each pair of anges.
63 4 5
1 8
2 7
51
3 7 2 6 4 8

4. l
k
1 2
3 4
5 6
7 8
t

5. WHEN TO PARALLEL LINES ARE CUT BY A
TRANSVERSAL
Parallel Alternate Interior Angle Postulate
“If two parallel lines are cut by a transversal, then any pair of
alternate interior angles are congruent.”
Parallel Alternate Exterior Angle Theorem
“If two parallel lines are cut by a transversal, then any pair of
alternate exterior angles are congruent.”
Parallel Corresponding Angles Theorem
“If two parallel lines are cut by a transversal, then the
corresponding angles are congruent.

6. 1. Why is
2. Why is
3. Why is
4. Why is
5. Why is
l
k
1 2
3 4
5 6
7 8
t
Directions: analyze the following statements below and give a corresponding
reason. Use “Parallel alternate interior angle postulate, parallel alternate exterior
angles theorem and parallel corresponding anglestheorem to be your answers.
3 7?  
4 5?  
8 1?  
2 6?  
5 8   ?