What type of angle is 90 degrees in the context of circle intersections?

An angle that measures 90 degrees is referred to as a right angle. In the context of circles, an inscribed angle is created when two chords in a circle intersect. The measure of an inscribed angle is half the measure of the arc that it intercepts.

When an inscribed angle is specifically 90 degrees, it means that the arc it intercepts measures 180 degrees, which is equivalent to a semicircle. This configuration is significant in circle geometry and often indicates that the endpoints of the arc are positioned at the endpoints of the diameter of the circle. As a result, the vertex of the inscribed angle lies on the circumference of the circle, fulfilling the definition of a right angle in this circular context.

This understanding of inscribed angles highlights their unique properties, particularly in relation to the arcs and circles they engage with. The presence of a right angle formed by an inscribed angle illustrates the interplay between angles and arcs within the geometry of circles.