What is the name of a triangle that includes one angle greater than 90 degrees?

A triangle that includes one angle greater than 90 degrees is known as an obtuse triangle. In geometry, triangles are categorized based on the measures of their angles. An obtuse triangle specifically has one angle that is obtuse, meaning it measures more than 90 degrees but less than 180 degrees. Because of this characteristic, the other two angles in the triangle must be acute (less than 90 degrees) in order to comply with the triangle sum theorem, which states that the sum of the interior angles of a triangle must equal 180 degrees.

The classification of triangles is crucial in geometry, and knowing the properties of obtuse triangles helps students understand different types of angles and how they relate to triangle formation. The other classifications, such as acute or right triangles, refer to different angle measures, while a scalene triangle is defined by having all sides of different lengths but does not necessarily specify angle measures.