Plane a.  Without elevations or depressions; even; level; flat; lying in, or constituting, a plane; as, a plane surface.
 Note: ☞ In science, this word (instead of plain) is almost exclusively used to designate a flat or level surface.
 Plane angle, the angle included between two straight lines in a plane.
 Plane chart, Plane curve. See under Chart and Curve.
 Plane figure, a figure all points of which lie in the same plane. If bounded by straight lines it is a rectilinear plane figure, if by curved lines it is a curvilinear plane figure.
 Plane geometry, that part of geometry which treats of the relations and properties of plane figures.
 Plane problem, a problem which can be solved geometrically by the aid of the right line and circle only.
 Plane sailing Naut., the method of computing a ship's place and course on the supposition that the earth's surface is a plane.
 Plane scale Naut., a scale for the use of navigators, on which are graduated chords, sines, tangents, secants, rhumbs, geographical miles, etc.
 Plane surveying, surveying in which the curvature of the earth is disregarded; ordinary field and topographical surveying of tracts of moderate extent.
 Plane table, an instrument used for plotting the lines of a survey on paper in the field.
 Plane trigonometry, the branch of trigonometry in which its principles are applied to plane triangles.


 Chart n.
 1. A sheet of paper, pasteboard, or the like, on which information is exhibited, esp. when the information is arranged in tabular form; as, an historical chart.
 2. A map; esp., a hydrographic or marine map; a map on which is projected a portion of water and the land which it surrounds, or by which it is surrounded, intended especially for the use of seamen; as, the United States Coast Survey charts; the English Admiralty charts.
 3. A written deed; a charter.
 Globular chart, a chart constructed on a globular projection. See under Globular.
 Heliographic chart, a map of the sun with its spots.
 Mercator's chart, a chart constructed on the principle of Mercator's projection. See Projection.
 Plane chart, a representation of some part of the superficies of the globe, in which its spherical form is disregarded, the meridians being drawn parallel to each other, and the parallels of latitude at equal distances.
 Selenographic chart, a map representing the surface of the moon.
 Topographic chart, a minute delineation of a limited place or region.