Point, straight, flat and space are geometric notions that have no definition and, for this reason, are called primitive notions gives Geometry. Let's get to know them better?
Point
O Score is used to mark locations in space. It was chosen for this because it has greater precision in this marking, since it has no format or dimensions.
With respect to dimensions of space, the point is called dimensionless, because it has no dimension. Therefore, it is impossible to take any measure of a point.
Marking a location by a point
straight
At straight they are sets of points aligned so that there is no curve. The points are one immediately after the other, filling all the spaces so that there are no “holes” in the straight line. They are infinite for two opposite directions and we can always notice two things:
There are infinitely many points on a line;
It is possible to measure the distance between them.
Note that it is not possible to measure the width of a straight line, only the distance between two of your points
. Therefore, we say that the straight line, with respect to the dimensions of space, is one-dimensional. Figures in which you can measure length and width, for example, are two-dimensional.We know that there are figures that cannot be drawn on a straight line. Note the square in the following figure:
Note that only two of your points belong to the straight and that the distance between these points represents the length of that square.
Flat
US plans, it is possible to measure lengths and widths. if we have a straight on a plane, there will be points outside of it that will also belong to that plane.
You plans are obtained by lining up straight lines so that they do not curve. They must be one immediately after the other so that there are no “holes” between them, and this queuing must be infinite for two directions. See an example:
About the plans it is possible to build two-dimensional figures such as square, triangle, circles etc.
Space
O space it is the “place” where you can measure length, width and depth. Thus, the space allows the creation of objects three-dimensional. It is infinite and unlimited in all directions, and its construction can be imagined from the queuing of plans.
By Luiz Paulo Moreira
Graduated in Mathematics
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