Types of triangles and their characteristics

Triangles are polygons formed by three sides and three angles. In geometric terms, triangles are the result of joining three non-collinear points (A, B and C).

The types of triangles vary according to the length of the sides and the internal angles formed by the vertices.

Check out the components and different types of triangles below.

Components of a triangle

The parts that make up a triangle are:

vertices: are the encounters between the lines that form the triangle. They are represented by the letters A, B and C.

sides: are the lines that form the triangle, connecting one point to another. They are represented by the letters a, b and c (in red).

angles: are the internal slopes formed by joining the sides. They are represented by the symbols α, β and θ.

Triangle classifications

Triangles can be classified with respect to their sides and with respect to their angles.

Classification of triangles by sides

With respect to sides, triangles can be:

Equilateral

Equilateral triangles are those that have three equal sides (same length) and, consequently, three equal internal angles of 60°. It can be called an equiangle.

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Scalene

Scalene triangles are those that have three different sides and, consequently, three different internal angles.

Isosceles

Isosceles triangles are those that have two equal sides (same length) and one different. Usually the different side is the base of the triangle, in which case the base angles will be equal.

Classification of triangles by angles

Regarding angles, triangles can be:

Rectangle

Right triangles are those that have a right angle, that is, an angle of exactly 90°.

In right triangles, the side opposite the right angle is called hypotenuse and the other sides are called peccaries. The other angles are acute and complementary, as their sum equals 90°.