undefined Terms bromheads.tv Topical outline | Geometry outline | MathBits" Teacher resources Terms that Use contact Person: Donna Roberts
In geometry, formal meanings are created using other identified words or terms. Over there are, however, 3 words in geometry that are not officially defined. These words room point, line and also plane, and are described as the "three undefined regards to geometry".
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While these words are "undefined" in the official sense, we deserve to still "describe" these words. The descriptions, stated below, describe these native in relationship to geometry.
POINT • a suggest indicates a place (or position) in space. • a point has no dimension (actual size). • a point has no length, no width, and no elevation (thickness). • a allude is usually called with a funding letter. • in the coordinate plane, a suggest is named by an notified pair, (x,y). if we stand for a point with a dot, the dot deserve to be very tiny or an extremely large. Remember, a allude has no size.
The dimension of the dot attracted to stand for a point makes no difference. Points have no size. They merely represent a location.
LINE (straight line) • a line has actually no thickness. • a line"s size extends in one dimension. • a line goes top top forever in both directions. • a line has actually infinite length, zero width, and also zero height. • a line is suspect to it is in straight. • a heat is attracted with arrowheads on both ends. • a heat is called by a solitary lowercase manuscript letter, or by any kind of two (or more) points i m sorry lie ~ above the line.
Lines deserve to be labeled with a solitary script letter, or by two points top top the line,
. The thickness of a line renders no difference.
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PLANE • a airplane has 2 dimensions. • a airplane forms a flat surface prolonging indefinitely in every directions. • a airplane has boundless length, limitless width and zero elevation (thickness). • a airplane is attracted as a four-sided number resembling a tabletop or a parallelogram. • a aircraft is called by a solitary letter (plane m) or by three coplanar, yet non-collinear,* point out (plane ABC).
plane m or plane ABC. If the diagram of a aircraft has edges, you must remember that the airplane actually has no boundaries.
* upright points are points the lie top top the exact same straight line. Coplanar points room points the line in the exact same plane.