Angle Relationships

Lines can be in the same plane or in different planes
When two lines are drawn in the same plane, they will either cross at one point or they will not cross at all

Parallel lines are lines in the same plane that never intersect

When lines cross, we say that they intersect. When they intersect and make square angles, we call the lines perpendicular

If lines intersect at a point but are not perpendicular, then the lines are oblique

Skew lines are lines that lie in different planes. They are neither parallel nor intersecting

Vertical angles are two nonadjacent angles formed by two intersecting lines. Vertical angles are congruent

Corresponding angles are on the same side of the traversal and are both above or below the parallel lines. Corresponding angles are congruent

Adjacent angles are side by side and have a common vertex and a common side

Alternate interior angles are on alternate sides of the traversal and are in the interior of the parallel lines. They are congruent

Alternate exterior angles are on alternate sides of the traversal and are outside of the parallel lines. They are congruent