When is a triangle classified as scalene?

A triangle is classified as scalene when all of its sides are of different lengths. This means that no two sides of the triangle are the same, leading to three distinct angles within the triangle as well. Because the lengths of the sides differ, the angles will also be unequal, which is a characteristic unique to scalene triangles.

In contrast, if a triangle has all sides equal, it is classified as equilateral. When two sides are equal, it is considered isosceles. The condition regarding one angle being greater than 90 degrees relates to the classification of triangles as obtuse but does not determine whether a triangle is scalene. Therefore, the defining feature of a scalene triangle is that all sides must be of different lengths, which is why this classification is accurate.