enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Parallel (geometry) - Wikipedia

    en.wikipedia.org/wiki/Parallel_(geometry)

    In geometry, parallel lines are coplanar infinite straight lines that do not intersect at any point. Parallel planes are planes in the same three-dimensional space that never meet. Parallel curves are curves that do not touch each other or intersect and keep a fixed minimum distance.

  3. Parallel postulate - Wikipedia

    en.wikipedia.org/wiki/Parallel_postulate

    This postulate does not specifically talk about parallel lines; [1] it is only a postulate related to parallelism. Euclid gave the definition of parallel lines in Book I, Definition 23 [2] just before the five postulates. [3] Euclidean geometry is the study of geometry that satisfies all of Euclid's axioms, including the parallel postulate.

  4. Skew lines - Wikipedia

    en.wikipedia.org/wiki/Skew_lines

    The line through segment AD and the line through segment B 1 B are skew lines because they are not in the same plane. In three-dimensional geometry, skew lines are two lines that do not intersect and are not parallel. A simple example of a pair of skew lines is the pair of lines through opposite edges of a regular tetrahedron.

  5. Parallel projection - Wikipedia

    en.wikipedia.org/wiki/Parallel_projection

    Parallel lines are mapped on parallel lines, or on a pair of points (if they are parallel to ). The ratio of the length of two line segments on a line stays unchanged. As a special case, midpoints are mapped on midpoints. The length of a line segment parallel to the projection plane remains unchanged. The length of any line segment is shortened ...

  6. Parallel curve - Wikipedia

    en.wikipedia.org/wiki/Parallel_curve

    Parallel curves of the implicit curve (red) with equation + = Generally the analytic representation of a parallel curve of an implicit curve is not possible. Only for the simple cases of lines and circles the parallel curves can be described easily. For example:

  7. Line at infinity - Wikipedia

    en.wikipedia.org/wiki/Line_at_infinity

    Also, if any pair of lines do not intersect at a point on the line, then the pair of lines are parallel. Every line intersects the line at infinity at some point. The point at which the parallel lines intersect depends only on the slope of the lines, not at all on their y-intercept. In the affine plane, a line extends in two opposite directions.

  8. Playfair's axiom - Wikipedia

    en.wikipedia.org/wiki/Playfair's_axiom

    Andy Liu [21] wrote, "Let P be a point not on line 2. Suppose both line 1 and line 3 pass through P and are parallel to line 2. By transitivity, they are parallel to each other, and hence cannot have exactly P in common. It follows that they are the same line, which is Playfair's axiom."

  9. Elliptic geometry - Wikipedia

    en.wikipedia.org/wiki/Elliptic_geometry

    Elliptic geometry is an example of a geometry in which Euclid's parallel postulate does not hold. Instead, as in spherical geometry , there are no parallel lines since any two lines must intersect. However, unlike in spherical geometry, two lines are usually assumed to intersect at a single point (rather than two).