Which type of triangle has one angle that is greater than 90 degrees?

A triangle with one angle that is greater than 90 degrees is classified as an obtuse triangle. This is a defining characteristic of obtuse triangles; they specifically contain one obtuse angle (greater than 90 degrees), which impacts the relationships of the remaining angles, as the sum of all angles in any triangle must always equal 180 degrees.

In contrast, an acute triangle consists only of acute angles, each measuring less than 90 degrees. A right triangle contains one angle that is exactly 90 degrees. Finally, a scalene triangle refers to a triangle where all three sides are of different lengths, and it can be either acute, right, or obtuse. Identifying triangles through their angles is key to understanding their properties and classifications in geometry.