Which type of triangle is characterized by having one angle greater than 90 degrees?

An obtuse triangle is specifically defined by the presence of one angle that measures greater than 90 degrees. This characteristic sets it apart from other types of triangles. In contrast, a right triangle has one angle that is exactly 90 degrees, and an acute triangle is defined as having all three angles measuring less than 90 degrees. An isosceles triangle refers to the equality of two of its sides and does not inherently relate to the measure of its angles. Thus, the defining feature of the obtuse triangle is its unique larger angle, making it the correct answer in this context.