We explain what geometric figures are and how they can be classified. We also explain their types and some examples of these figures.
What is a geometric figure?
A geometric figure is the visual representation of a shape that can have different characteristics. It can be made up of a point, a line, or a set of lines that connect its points in a specific way.
Being representations, geometric figures are abstract, meaning they are the product of thought and, therefore, do not exist in reality. However, they can be drawn, and in the physical world, many objects exist that adopt their shapes. You must read about Perimeter once.
Geometric figures are classified according to different criteria, such as their dimensions, shape, and number of sides.
Types and Examples of Geometric Figures
According to their number of dimensions, geometric figures are classified as dimensionless, linear, two-dimensional (or flat), and three-dimensional (or volumetric) figures.
Dimensionless Geometric Figures
Dimensionless geometric figures are those that have no dimension, that is, they have no length, width, or depth. A point is a dimensionless geometric figure.
Linear Geometric Figures
Linear geometric figures are those that have only one dimension. They are lines with a specific orientation and a specific path. Linear geometric figures are:
- Straight line. It is a straight line.
- Curved line. It is an oblique line.
Two-Dimensional or Flat Geometric Figures
Two-dimensional or flat geometric figures are those that have two dimensions: width and length. There are two main groups of these figures: polygons and curved figures.
Polygons. Their lines join to form closed figures. They have sides, vertices, and angles. They are classified according to the number of sides they have and their shape.
According to their number of sides, polygons can be:
Triangles
They have three sides, and depending on their shape, they are classified as:
- Equilateral triangles: They have three equal sides.
- Isosceles triangles: They have two equal sides and one different side.
- Scalene triangles: They have all different sides.
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Quadrilaterals
They have four sides and, depending on their sides and angles, they can be:
- Squares: They have four 90° angles and four equal sides.
- Rectangles: They have four 90° angles and two pairs of identical sides.
- Rhombi: They have four equal sides, and one pair of angles greater than 90° and another pair less than 90°.
- Rhomboids: They have two pairs of equal sides, two angles less than 90°, and two more than 90°.
- Trapezoids: They have four sides, and the top one is always smaller than the bottom one.
- Pentagons: They have five sides.
- Hexagons: They have six sides.
- Heptagons: They have seven sides.
- Octagons: They have eight sides.
- Nonagons: They have nine sides.
- Decagons: They have ten sides.
Curved figures. They have at least one curved line. The most common are:
- Circles: These are figures in which all points on the line have the same distance from the center.
- Ovals or ellipses: These are like a flattened and elongated circle because they are symmetrical, but some points on the line are farther from the center.
Three-dimensional or volumetric geometric figures
Three-dimensional or volumetric geometric figures have three dimensions: width, length, and depth. Therefore, they have volume. They are classified as polyhedrons and round bodies:
Polyhedrons
They are made up of several flat faces, which are polygons and which are all connected. They also have vertices and edges. For example:
- Cubes: They have six faces that are squares.
- Prisms: They have two equal, facing bases that are polygons, and other faces that are always quadrilaterals. The number of faces is determined by the sides of the polygons that form the bases.
- Pyramids: They have a single base, which is a polygon, and faces that are triangles and that join at the top to form a vertex.
- Tetrahedrons: These are a type of pyramid whose base and faces are equilateral triangles.
Round bodies: They are made up of at least one curved face. For example:
- Spheres: They have a single face that is completely round.
- Cylinders: They have two bases that are identical circles, and a curved face that connects the two bases.
- Cones: They have a base that is a circle, and a face that extends from the base and ends in a vertex.
References
All the information we offer is supported by authorized and updated bibliographic sources, ensuring reliable content in line with our editorial principles.
- Godino, J. D. & Ruiz, F. (2002). Geometry and its teaching for teachers. Department of Mathematics Didactics, Faculty of Education Sciences, University of Granada.
- Medina, H. (2022). Geometric Figures. Encyclopedia of Mathematics. enciclopediadematematica.com
- Ministry of Education of Ecuador (2016). Mathematics 8. Student Text. SM. educacion.gob.ec
- Universo Fórmulas. (2024). Geometric Figures. universoformulas.com
