What type of triangle has one angle greater than 90 degrees?

The type of triangle that has one angle greater than 90 degrees is called an obtuse triangle. An obtuse triangle is defined by the presence of one obtuse angle, meaning that this angle measures more than 90 degrees but less than 180 degrees. In contrast, the other angles in the triangle will be acute, meaning they each measure less than 90 degrees.

Understanding the characteristics of different triangles is crucial in geometry. An acute triangle contains all angles that are less than 90 degrees, so it cannot have an angle that exceeds 90 degrees. A right triangle, by definition, has one angle measuring exactly 90 degrees and cannot contain an obtuse angle. Lastly, an equilateral triangle features three equal angles, each measuring exactly 60 degrees, which again falls short of being obtuse.

This differentiation between triangle types is a fundamental concept in geometry, helping to categorize shapes based on their angle measures.