Which angle type is defined as equal to 90 degrees?

A right angle is defined specifically as an angle that measures exactly 90 degrees. This measurement means that it forms a perfect corner, dividing a full rotation into four equal parts. In most geometric contexts, right angles are significant in various applications, such as in the construction of buildings and in many mathematical problems involving shapes like squares and rectangles, where they are essential for establishing perpendicular lines.

The specific definition of a right angle differentiates it from other types of angles. An acute angle measures less than 90 degrees, while an obtuse angle measures more than 90 degrees but less than 180 degrees. A straight angle is exactly 180 degrees, representing a straight line. Recognizing these distinctions is crucial in understanding angle relationships and properties in geometry.