We explain what geometric figures are and the ways in which they can be classified. Also, some examples of these figures.
What is a geometric figure?
A geometric figure is the visual and functional representation of a non-empty and closed set of points in a geometric plane. That is to say, figures that delimit plane surfaces through a set of lines (sides) that connect their points in a specific way. Depending on the order and number of these lines we will talk about one figure or another.
Geometric figures are the working stuff of geometry, branch of mathematics that studies representational planes and the relationships between the forms that we can imagine in them. They are, therefore, abstract objects, according to which our perspective and our way of spatially understanding the universe that surrounds us is determined.
Geometric figures can be classified according to their shape and number of sides, but also based on the number of dimensions represented, and can thus speak of:
- Dimensionless figures (0 dimensions). It basically refers to the point.
- Linear figures (1 dimension). They are straight lines and curves, that is, lines with a certain orientation and path.
- Flat figures (2 dimensions). Polygons, planes, and surfaces, which lack depth but have measurable length and width.
- Volumetric figures (3 dimensions). Three-dimensional figures add depth and perspective to the subject, and can be considered geometric bodies, such as polyhedra and solids in revolution.
- N-dimensional figures (n-dimensions). These are theoretical abstractions endowed with n quantity of appreciable dimensions.
We should note that to define the geometric figures abstractions such as point, line and plane are often used, which are in turn considered figures of geometry.
Examples of geometric figures
Some examples of geometric figures are:
- Triangles Flat figures characterized by having three sides, that is, three lines in contact forming three vertices. Depending on the type of angle that they construct, they could be equilateral triangles (three equal sides), isosceles (two equal and one different) or scalenes (all unequal).
- Squares. These plane figures are always identical in proportion but not in size, having four sides necessarily of the same length. Its four angles will then be right angles (90 °).
- Rhombuses. Similar to the square, they have four identical sides in contact, but none constitute right angles, but acute and two obtuse.
- Circumferences. It is a flat curve closed on itself, in which any chosen point on the line is the same distance from the center (or axis). It could be called a perfect circle.
- Ellipses. Closed curves similar to the circumference, but with two axes or centers instead of one, generating a flattened or elongated spheroid, depending on whether it rotates around its minor or major axis, respectively.
- Pyramids Three-dimensional geometric bodies formed by a quadrangular base and four isosceles triangles that act as sides.