There is a relation between the lengths of the sides of a triangle.
It's very simple to remember and can be easily understood:
Always, in any triangle, the sum of the lengths of two sides will be greater than the third.
That is, there is no possibility that adding the length of two sides will give us less than the length of the third side.
It will always give us a length greater than that of the third side.
This relationship is very intuitive and logical since, generally, when we join two quantities or sizes the result is larger than not joining them.
![1.a - image 1- relationship between the lengths of the sides of a triangle](/_ipx/f_png,s_500x478/https://cdn.tutorela.com/images/1.a_-_imagen_1-_relacion_entre_las_longitudes_.width-800.png)