Which is the best definition of a scalene triangle?

Which is the best definition of a scalene triangle?

A scalene triangle is a triangle with all the three unequal sides. None of its sides is equal to any other.

But like other triangles, all the angles inside a scalene triangle add up to 180 degrees.

Like if a triangle has sides 5 cm, 2 cm and 6 cm. Then it will be a scalene triangle.

Each side of the triangle has different lengths