A scalene triangle has no parallel sides and no equal angles. The three noncongruent sides of a scalene triangle are of different lengths, and the measurements of the three unequal angles inside the triangle, like those of all triangles, add up to a total of 180 degrees.
In a scalene triangle, the longest side is across from the largest angle, and the smallest side is opposite the smallest angle. A scalene triangle is a stable triangle. It is used in roof trusses, bicycle frames, automobiles, bridges and ramps. There is also a group of three muscles of different lengths in the human neck called the scalene muscles.