Transversal Definition: A line intersecting two or more other lines in a plane. Picture:

Corresponding Angles Definition: Angles that are in the same relative position. Picture:

Corresponding Angles Conjecture Conjecture: If two parallel lines are cut by a transversal, the corresponding angles are congruent. Picture:

Alternate Interior Angles Definition: On the “inside” and opposite side of the transversal. Picture: ∠4 and ∠5 𝐨𝐫∠6 and ∠3

Alternate Interior Angles Conjecture Conjecture: If two parallel lines are cut by a transversal, then the alternate interior angles are congruent. Picture:

Alternate Exterior Angles Definition: On the “outside” and opposite side of the transversal. Picture: ∠1 and ∠8 𝐨𝐫 ∠7 and ∠2

Alternate Exterior Angles Conjecture Conjecture: If two parallel lines are cut by a transversal, then the alternate exterior angles are congruent. Picture:

Parallel Line Conjecture Type of Angle Special Feature Corresponding Angles Congruent Alternate Interior Angles Alternate Exterior Angles

Let’s Practice… If ∠𝑀𝐿𝑁 = 105, what are the measures of the other 7 angles?

Let’s Practice… If ∠3 = 97, what are the measures of the other 7 angles?

Let’s Practice… If ∠ℎ = 60, what are the measures of the other 7 angles?