What is the term for a triangle with one angle measuring 90 degrees?

A triangle with one angle measuring 90 degrees is referred to as a right triangle. This classification is based on the unique property that distinguishes right triangles from other types of triangles. In geometry, a right triangle features one angle specifically equal to 90 degrees, which is the defining characteristic. The presence of this right angle allows the use of the Pythagorean theorem, which relates the lengths of the sides of the triangle.

In contrast, an obtuse triangle has one angle measuring greater than 90 degrees, while an acute triangle has all three angles measuring less than 90 degrees. A scalene triangle, on the other hand, is defined by having all sides of different lengths, which can include right triangles as a subtype. Thus, the term that specifically denotes a triangle with a 90-degree angle is a right triangle.