What type of triangle has no equal side lengths?

A triangle that has no equal side lengths is classified as a scalene triangle. In geometrical terms, a scalene triangle is characterized by having all three sides of different lengths, which also means that all three angles inside the triangle will be different. This distinct feature differentiates it from other types of triangles such as isosceles, where at least two sides are equal, and equilateral, where all sides are the same length.

The right triangle, which is another option, can have a mix of side lengths; it may have two sides of equal length, thus it doesn't fit the definition of having no equal sides. Therefore, the scalene triangle stands out as the only triangle type within the given choices that consistently maintains unequal side lengths.