The definition of an acute angle is one that is less than 90 degrees.
An example of an acute angle is one that is 85 degrees.
An angle whose measure is between 0° and 90°.
American Heritage Science
Other Word Forms of Acute Angle
Acute Angle Sentence Examples
The branches grow at a more acute angle.
Jaw formed of folds imbricated externally and meeting at an acute angle near the base.
The right and left hepatic ducts, while still in the transverse fissure, unite into a single duct which joins the cystic duct from the gall bladder at an acute angle.
Now the position of this line, as found by Kobold, actually is a (properly weighted) mean between the corresponding lines of symmetry of the two drifts, but naturally it lies in the acute angle between them, whereas the line of the solar motion is also a weighted mean between the two lines of drift, but lies in the obtuse angle between them.
Successive halfturns about intersecting axes a, b are equivalent to a rotation about the common perpendicular to a, b at their intersection, Of amount equal to twice the acute angle between them, in the direction from a to b.