FTCE General Knowledge Math Practice Test

What type of triangle is characterized by having exactly one obtuse angle?

1. Acute triangle

2. Right triangle

3. Scalene triangle

4. Obtuse triangle

The correct answer is: Obtuse triangle

A triangle characterized by having exactly one obtuse angle is known as an obtuse triangle. In this type of triangle, one angle measures more than 90 degrees, while the other two angles must each measure less than 90 degrees, ensuring that the sum of all angles remains 180 degrees. This distinct feature differentiates obtuse triangles from other triangle types. For instance, an acute triangle has all angles measuring less than 90 degrees, and a right triangle contains one angle that is exactly 90 degrees. A scalene triangle is defined by having all sides of different lengths, which does not necessarily imply anything about the angles. Thus, the defining characteristic of having one obtuse angle clearly aligns with the concept of an obtuse triangle.