What type of triangle is defined by having one angle greater than 90 degrees?

A triangle that has one angle greater than 90 degrees is classified as an obtuse triangle. This characteristic is fundamental to the definition of the triangle's types based on their angles. An obtuse triangle will always have one obtuse angle, which is the angle exceeding 90 degrees, while the other two angles must be acute (less than 90 degrees) in order for the sum of all angles in any triangle to equal 180 degrees.

In contrast, an acute triangle has all angles measuring less than 90 degrees, while a right triangle has one angle exactly equal to 90 degrees. A scalene triangle refers to a triangle where all sides and angles are unequal but does not specifically define the angles in terms of being acute or obtuse. Therefore, the classification of obtuse accurately captures the specific trait of having an angle that exceeds 90 degrees.