right angle

noun

1. the angle formed by two radii of a circle that are drawn to the extremities of an arc equal to one quarter of the circle; the angle formed by two perpendicular lines that intersect; an angle of 90°.

noun

1. the angle between two radii of a circle that cut off on the circumference an arc equal in length to one quarter of the circumference; an angle of 90° or π/2 radians
2. at right angles perpendicular or perpendicularly

1. An angle having a measure of 90°.

An angle measuring ninety degrees, formed by the intersection of two perpendicular lines. (Compare acute angle and obtuse angle.)