test Flashcards
Parallel lines
lines in the same plane that have no points in common
Perpendicular lines
lines that intersect to form right angles (90°)
Parallel Lines Theorem
In a coordinate plane, two nonvertical lines are parallel if and only if they have the same slope. Any two vertical lines are parallel.
Perpendicular Lines Theorem
In a coordinate plane, two nonvertical lines are perpendicular if and only if the product of their slopes is −1. Vertical and horizontal lines are perpendicular.
Parallel lines (||)
they are coplanar and do not intersect
Perpendicular lines (⊥)
they intersect at 90° angles.
Skew lines
they are not coplanar. Skew lines are not parallel and do not intersect.
Parallel planes
they are planes that do not intersect.
A transversal
a line that intersects two coplanar lines at two different points.
Corresponding angles
they lie on the same side of the transversal and on the same side of the other two lines.
Alternate interior angles
they are nonadjacent angles that lie on opposite sides of the transversal and between the other two
lines.
Alternate exterior angles
they lie on opposite sides of the transversal and outside the other two lines.
Same-side interior angles
they lie on the same side of the transversal and between the other two lines.
perpendicular bisector
(of a segment) is a line perpendicular to a segment at the segment’s midpoint
slope formula
m = y2 - y1/x2 - x1
