What do you call a triangle that has three acute angles?

A triangle that has three acute angles is referred to as an acute triangle. By definition, an acute angle is one that measures less than 90 degrees. In an acute triangle, since all three angles are acute, each angle measures less than 90 degrees. This property distinguishes acute triangles from right triangles, which have one angle that is exactly 90 degrees, and from obtuse triangles, which have one angle greater than 90 degrees. The term scalene refers to a triangle in which all sides and angles are different; it does not necessarily indicate anything about the measure of the angles. Therefore, the designation of a triangle as acute directly connects to all of its angles being less than 90 degrees, making "acute triangle" the correct classification for this type of triangle.