In geometry and trigonometry, a right angle is an angle of exactly 90° (degrees), corresponding to a quarter turn. If a ray is placed so that its endpoint is on a line and the adjacent angles are equal, then they are right angles.
The acute angle is the small angle which is less than 90°. If you choose the larger angle you. will have a Reflex Angle instead: The smaller angle is an Acute Angle, but the larger angle is a Reflex Angle.
In geometry, there are five types of angles. An obtuse angle is greater than 90 degrees but less than 180 degrees. An acute angle is less than 90 degrees, A right angle is exactly 90 degrees. A straight angle is exactly 180 degrees, and a reflex angle is greater than 180 degrees.
