A 90-degree angle is called a right angle.
It is one of the most common and easily recognisable angles, forming an L shape. Right angles are used as a standard reference in design, construction and manufacturing because of their precise geometry. Many plastic profiles, including angle trims, are extruded with a fixed 90-degree shape to fit corners or edges cleanly. At MKM Extrusions, these are made from external grade PVC and are referred to as plastic angle trims, corner trims and corner joints.