secant plane
{{about|the cross-section of the sphere||Secant (disambiguation)}}
File:Ellipsoid_circular_sections.gif
A secant plane is a plane containing a nontrivial section of a sphere or an ellipsoid, or such a plane that a sphere is projected onto. Secant planes are similar to tangent planes, which contact the sphere's surface at a point, while secant planes contact the surface along curves.
The two-dimensional representations of secant planes are secant lines, the lines that join two distinct points on a curve.
Applications
{{comparison_of_cartography_surface_development.svg|300px}}
Secant planes are used in map projections. The secant plane intersects a globe along a small circle with no distortion, forming a standard parallel which has true scale.{{Cite web|url=http://geokov.com/education/map-projection.aspx|title=Map projection - types and distortion|last=|first=|website=geokov.com|access-date=2016-11-02}}
See also
References
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External links
- [http://www.geo.hunter.cuny.edu/~jochen/gtech201/lectures/lec6concepts/Map%20coordinate%20systems/Tangents%20and%20secants.htm Tangents and Secants in Map Projections]