The isosceles triangle has very particular characteristics that distinguish it, for example, from the scalene and equilateral triangle. The term isosceles has its origin in the Greek that results from “iso = equal, skeles = legs”; that is, we find ourselves with a polygon figure in which precisely two of the sides, yes or yes, are equal. The third by deduction is unequal .
This means that of the three angles that are formed, two are similar while the third is different. Of course, a basic rule must be fulfilled, which is that the sum of the three angles must result in a total of 180 degrees. From the historical point of view, this denomination and property was demonstrated by the Greek philosopher known as Thales of Miletus.
Types of isosceles triangles
Isosceles acute triangle
This type of triangle is generally known for the reason that the resulting angles are usually acute, that is, two of these are similar to each other in degree while the third is not. The distinctive feature is the fact that the height of both sides corresponding to similar angles is symmetrical to each other.
Isosceles obtuse triangle
In this case, to classify a triangle within this group that must be isosceles in the first instance, it must be observed and determined that they have two sides that are equal to each other. The third side, which by deduction is always different, must be greater than the other two to be considered this type of triangle. That is the main feature to be observed.
Isosceles right triangle
In this case, for its classification and/or distinction, the same rule is followed, that is, it must be observed that two of its sides are equal to each other and a third different. The property observed in this case is that equal sides project angles of 45 degrees each. Consequently, a third side will come out through the line so that 180 degrees are added to the angles, a straight one.