What is a triangle with three congruent sides called?

A triangle with three congruent sides is categorized as an equilateral triangle. In this type of triangle, all three sides are equal in length and, as a result, all three interior angles are also equal, each measuring 60 degrees. This property of equal sides and angles is what distinctly characterizes equilateral triangles, setting them apart from other types of triangles.

In contrast, a scalene triangle has no sides that are of equal length, meaning all three sides are different, and consequently, all interior angles are also different. An isosceles triangle has at least two sides that are equal in length with the angles opposite those sides being equal as well, which does not fit the definition of having three equal sides. An obtuse triangle, on the other hand, is defined by having one angle that is greater than 90 degrees, and it may have any configuration of side lengths. Therefore, equilateral is the precise term used for a triangle where all three sides are congruent.