Are the angles adjacent? Do they lie on the same side or different sides of the transversal?
Transversal: Line p Angles: Alternate interior
Practice makes perfect
A transversal is a line that intersects two or more coplanar lines at two different points. Now, let's analyze ∠ 7 and ∠ 2 on the given diagram.
As we can see, ∠ 2 and ∠ 7 are formed by line m and line n and transversal p. They do not share any side or a point, so they are nonadjacent. Also, ∠ 2 and ∠ 7 are interior angles that lie on opposite sides of the transversal. Therefore, the angles are alternate interior angles.
Extra
Transersal Angle Pair Relationships
Let's review all of the transversal angle pair relationships. We will use the graph below as an example.
Now let's take a look at the different types of angle pairs and their definitions.
Pairs of Angles
Type
Definition
Example
Interior Angles
They lie in the region between lines a and b.
∠ 4 and ∠ 5
Exterior Angles
They lie in the two regions that are not between lines a and b.
