A right angle is an angle that measures exactly 90 degrees. It is one of the most fundamental concepts in geometry and is often represented by a small square in the corner of the angle. Right angles are commonly found in various shapes, such as squares and rectangles, where the sides meet at these angles. In practical applications, right angles are essential in construction and design. They ensure that structures are level and stable. Tools like the carpenter's square are used to create and check right angles, helping builders achieve accuracy in their work.