If a transversal intersects two parallel lines, then corresponding angles are congruent.
We can visualize this theorem. Consider two lines l and m, where l∥ m.
Applying the theorem, we can identify the first congruent angle from the given diagram.
m∠5 = 51^(∘)
Next, we will use the Vertical Angles Theorem.
Vertical Angles Theorem
If two angles are vertical, then they are congruent.
We can illustrate this theorem as well. Once again, assume that l∥ m.
Applying this theorem, we can find two more congruent angles.
m∠4 and m∠7
Now that we've found all of the possible congruent angles, let's mark them on the diagram.
