Which type of triangle can have angles that are all less than 90 degrees?

A triangle with all angles measuring less than 90 degrees is classified as an acute triangle. To meet this requirement, the internal angles must each be greater than 0 degrees but less than 90 degrees.

An acute triangle can have varying side lengths, which means it can also be scalene—where all three sides are of different lengths. However, the defining characteristic is the angle measure, specifically that each angle must remain acute.

In contrast, a right triangle contains one angle that measures exactly 90 degrees, and an obtuse triangle has one angle that exceeds 90 degrees. Therefore, neither of these types supports the condition of having all angles less than 90 degrees.