A half turn is 180° and is known as a straight angle (or angle on a straight line). A three-quarter turn is 270°. An acute angle is less than 90°. An obtuse angle is between 90° and 180°.

Pulled far out of court by an Anna Blinkova forehand in the Mutua Madrid Open second round, Aryna Sabalenka responded with a ridiculously sharp angle of her own.