U1C5: Parallel and Perpendicular Lines Flashcards
perpendicular bisector
a line or line segment that is perpendicular to another segment and cuts the segment into two congruent segments
concurrent lines
a set or two or more lines that intersect in only one point
coincide
two lines that have more than one intersecting point
transversal
a line that crosses two or more other lines
alternate interior angles
the pairs of angles on opposite sides of the transversal but inside the two lines
alternate exterior angles
the pairs of angles in opposite sides of the transversal but outside the two lines
perpendicular lines theorem
if two lines intersect and one of the angles is 90 degrees the lines are perpendicular
property 1 of perpendicular bisectors
the distances of any point on the perpendicular bisector from both endpoints of the line being bisected are the same
property 2 of perpendicular bisectors
if any point on the perpendicular bisector is connected to the endpoints of the segment being bisected, the angles formed at the endpoints are congruent
if a line is parallel to one set of parallel lines
then it is parallel to all those lines
if a transversal intersects a set of parallel lines
then it intersects all the other lines
from a point not on a line, how many lines can be drawn parallel to a given line
one and only one line
if two or more lines are perpendicular to a set of parallel lines
then they are parallel
if two or more lines are perpendicular to a pair of parallel lines
then the intercepted parts of the perpendicular lines are equal
if two lines are perpendicular to the same plane
then they are coplanar
