FTCE Professional Education Practice Exam

What is a characteristic of a scalene triangle?

1. It has at least one equal side

2. It has all sides equal

3. All angles are less than 90 degrees

4. It has no sides equal

The correct answer is: It has no sides equal

A scalene triangle is defined by the unique characteristic that it has no sides of equal length. This distinction sets it apart from other types of triangles, such as isosceles triangles, which have at least two sides that are equal, and equilateral triangles, where all three sides are equal. The absence of equal sides in a scalene triangle means that its angles are also all different from one another, although they do not necessarily have to be less than 90 degrees. Consequently, while some scalene triangles can be acute (with all angles less than 90 degrees) or obtuse (with one angle greater than 90 degrees), the defining characteristic remains that no sides share the same length. This foundational property of having all sides of different lengths is what categorizes a triangle as scalene.