Today we will define everything related to types of triangles. Those figures that for years have determined many functions and activities in humanity, have been the subject of studies and today are used to give value and strength to designs, structures and above all, they provide elements for knowledge.


Types of triangles

When determining these geometric figures we must also consider the types of triangles and their characteristics as well as its use. In such a way that, they are geometric figures made up of three sides and three angles, either closed or open, depending on the type of vertex. Triangles are represented mostly with lowercase letters, they are the division of a square, a trapezoid, rhombus or rectangle.

These geometric figures are actually three-sided polygons. It is the smallest figure that exists among the various that are presented in arithmetic and drawing; next to the square, pentagon, hexagon, heptagon, octagon, hendecagon and decagon; Although there are many others, it is considered one of the most important ones.

All types of triangles and their names They can be classified according to their sides or according to their angles, also determined by open or closed angles, they usually have elements that help them define certain parts of their figure, but we see the types,

According to its sides

In this classification we will detail each of the triangles according to the sides that make it up, some are longer, others the same but always determined by the length and shape of the lines.

Equilateral, is one that has all its sides equal, that is, each line has the same length.

Isosceles, the triangle is considered in which two of its sides measure the same and the remaining one has a different length.

Scalene, is the triangle in which all its sides have different lengths.

According to their angles

They are those triangles determined according to the value in each of their angles. This determines the highest or lowest vertex, depending on the number of degrees contained in the union of the lines.

  • Rectangle, is that triangle where one of its sides has a right angle, that is, it forms a 90 degree vertex.
  • Acute angle, consists of a triangle in which two of its vertices have acute angles, that is, less than 90 degrees, (in this case also the right triangle is also a rectangle since two of its angles have less than 90 degrees.
  • Scalene, is considered the triangle in which two of its angles form an obtuse angle, so that they are greater than 90 degrees.
  • One way of considering the triangle as a geometric figure is determined by the sum of its angles. If a square must have 360 ​​degrees after adding all its sides, the triangle is half of a four-sided figure, for this reason the sum of its angles must be 180 degrees.

Elements of a triangle

Each geometric figure determined as a triangle contains a series of elements that identify and differentiate it from another figure. The lines are the elements that exist within it, so let's see what they are:

  • Median, it is a line that passes through the center of the triangle called the barycenter, joins each vertex with the center of the figure and lies on the opposite line.
  • Angles, determined by the inclination of each line in the triangle, can be acute, right or obtuse.
  • Vertex, just as the angles are created by the union of the lines, form the external points and are also configured to varying degrees, mostly obtuse.
  • Barycenter, the central point of the triangle is considered when all the lines that start from the vertex and join the midpoint are joined.
  • Bisector, is a line that divides the triangle into two equal areas, to locate it a certain arithmetic procedure must be performed, not all triangles are equal.
  • Mediatrix, is a perpendicular line that starts from the central points of the sides of the figure, they are also called circumcenter.
  • Orthocenter or height, is a vertical line that measures the real height of a triangle according to the perpendicular segments that start from the vertex to its opposite side, they should not be confused with the median lines.


As a geometric figure, it is made up of various elements and factors that allow describing various specifications and characteristics, among the most prominent we have.

  • They all have three vertices.
  • Likewise, they have three sides and three angles no more
  • The sum of its simple angles will yield 180 degrees.
  • For its part, the sum of its external sides add up to 360 degrees
  • In right triangles, so-called trigonometric processes are formed where the shortest sides are called legs and the longest are called the hypotenuse.
  • The formation of trigonometry is based on the ratio of the quotient between each side.
  • The sine is the quotient of the leg opposite the hypotenuse.
  • The cosine belongs to the leg adjacent to the hypotenuse.
  • The Tangent represents the quotient between the opposite leg and the adjacent leg.
  • The cosecant is the coefficient of the hypotenuse and is found on the opposite leg.
  • Secant, is the quotient of the hypotenuse found between the adjacent leg.
  • Cotangent: The quotient u exists between the adjacent leg and the opposite leg is considered.
  • They are complements of the rest of the regular and star polygons.


We already know cHow many types of triangles are thereThese have served for thousands of years: they have served to increase knowledge related to geometry. Its shape allows to develop firm figures and structures that can generate great durability over time. The design for the elaboration of the triangles is related to the way in which the pyramids should be created.

Today the study of triangles is directly related to mathematics, where in recent years studies have been achieved where its application in society. It also serves for the study of trigonometry, which allows it to be applied in areas such as architecture, design and engineering.

In the following article you can learn about aspects related to this topic, don't miss it Rectangle and square area.