In a right triangle, what is the measure of one angle?

In a right triangle, one of the angles is defined to be a right angle, which measures precisely 90 degrees. This is a fundamental characteristic of right triangles, distinguishing them from other types of triangles. The other two angles in a right triangle must be acute angles that are less than 90 degrees, and together they will sum up to 90 degrees, ensuring that the total measure of the angles in any triangle—right triangle included—adds up to 180 degrees. Thus, the presence of a 90-degree angle is what categorizes the triangle as a right triangle.