What is the best definition of a scalene triangle?

A scalene triangle is defined as a triangle in which all three sides have different lengths, resulting in all three angles being different as well. This lack of equal sides distinguishes it from isosceles and equilateral triangles, which have at least two equal sides or all three equal sides, respectively. Scalene triangles can come in various forms, including acute, right, or obtuse, depending on the measures of their angles.