Geometry Chapter 3
Transversal
A line that intersects two or more lines in a plane at different points is called a transversal
Non-Euclidean geometry
Spherical geometry is one type of non-Euclidean geometry
if and only if
If both a conditional and its converse are true, it can be written in if and only if form
Parallel Postulate
If there is a line and a point not on the line, then there exists exactly one line through the point that is parallel to the given line.
Slope
In a coordinate plane, the slope of a line is the ratio of its vertical rise to the horizontal run.
Spherical geometry
a system of points, great circles (lines), and spheres (planes)
plane Euclidean geometry
A system of points, lines and plans
Equidistant
Equidistant means that the distance between two lines measured along a perpendicular line to the line is always the same.
alternate exterior angles, alternate interior angles, consecutive interior angles, corresponding angles, interior angle, exterior angle
See page 126 of the text
Distance between parallel lines
The distance between two parallel lines is the distance between one of the lines and any point on the other line.
Distance between a point and a line
The distance from a line to a point not on the line is the length of the segment perpendicular to the line from the point.
Skew lines
Two lines are skew if they do not intersect and are not in the same plane.
Parallel lines
Two lines in a plane that never meet are called parallel lines