A scalene triangle has zero lines of symmetry.

A scalene triangle is defined as a triangle in which all three sides and all three angles are different. Because there are no equal sides or angles, you cannot draw any line that would divide the triangle into two identical halves. Unlike isosceles or equilateral triangles, which have at least one or more lines of symmetry due to their equal sides or angles, a scalene triangle lacks this feature entirely. This makes it an interesting case in geometry, highlighting how variations in triangle properties affect their symmetrical characteristics.