Secant plane

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Animation showing the circular secant planes of the ellipsoid Ellipsoid circular sections.gif
Animation showing the circular secant planes of the ellipsoid

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.

Contents

The two-dimensional representations of secant planes are secant lines, the lines that join two distinct points on a curve.

Applications

Comparison of tangent and secant cylindrical, conic and azimuthal map projections with standard parallels shown in red Comparison of cartography surface development.svg
Comparison of tangent and secant cylindrical, conic and azimuthal map projections with standard parallels shown in red

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. [1]

See also

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References

  1. "Map projection - types and distortion". geokov.com. Retrieved 2016-11-02.