Which type of triangle has all three angles measuring less than 90 degrees?

An acute triangle is defined as a triangle in which all three interior angles are less than 90 degrees. This characteristic distinguishes acute triangles from other types, such as right triangles, which contain one angle measuring exactly 90 degrees, and obtuse triangles, which have one angle greater than 90 degrees.

While isosceles and scalene triangles refer to the lengths of their sides (isosceles having two sides of equal length, and scalene having all sides of different lengths), they can also be acute, right, or obtuse. However, the defining feature of an acute triangle solely pertains to the measure of its angles. Therefore, the option indicating that it is an acute triangle is indeed the correct response, as it accurately encapsulates the requirement that all angles in the triangle remain under 90 degrees.