acute angle

noun

plural acute angles

mathematics

: an angle (see angle entry 1 sense 1a) measuring greater than 0 degrees and less than 90 degrees

New England's highway engineers embraced the rotary as the replacement for centuries-old … sites where many roads combined at odd, often acute angles.

—John R. Stilgoe

[Tennis player Naomi] Osaka crashes a shot into the net but comes back with two forehand winners, the second from an acute angle nearly around the net, to move within a game of victory.

—The Guardian (London)

Inspect your tree for limbs that branch from the central leader either too sharply upward, forming an acute angle, or at too wide an angle.

—Carol Savonen

compare obtuse angle, right angle

Word History

First Known Use

circa 1560, in the meaning defined above