Angles are based on parts of a full turn, which is 360°. A quarter turn is 90° and is called a right angle. A half turn is 180° and is known as a straight angle (or angle on a straight line).

One that I hear a lot is that you must never put a 90-degree angle on a trace. Some fear the mere sight of a 90-degree angle on a PCB tells everyone you don’t know what you’re doing.

Although players frequently COD at >90° angles, limited knowledge is available on knee joint kinematics and kinetics during COD at 90° and 135° and whether limb preference impacts knee mechanics ...

This pivoting hinge stands out for its firm hold at 90-degree angles. The term "Fx" is derived from "fix," highlighting its ability to keep the door in place through powerful retention points.