What is a Right Angle?

A right angle is an angle that measures exactly 90 degrees (or π/2 radians). It corresponds to a quarter of a full 360-degree rotation.

When two straight lines intersect to form a right angle, they are said to be perpendicular or orthogonal to one another. Visually, a right angle forms a perfect "L" shape and is typically denoted in geometric diagrams by a small square drawn at the vertex (the meeting point of the two lines).

The presence of a right angle is what defines a right triangle, which is the exact geometric shape solved by our Right Angle Calculator Triangle tool. In a right triangle, the side located directly across from the right angle is called the hypotenuse.