In which type of triangle are all angles acute?

An acute triangle is defined as a triangle in which all three interior angles measure less than 90 degrees. This property ensures that each angle remains sharp or "acute," contributing to the overall classification of the triangle as acute.

In contrast, a right triangle features one angle that exactly measures 90 degrees, while an obtuse triangle has one angle exceeding 90 degrees. An isosceles triangle does not inherently define the nature of its angles, as it can be classified into any type based on its angle measurements. However, if an isosceles triangle has all angles measuring less than 90 degrees, it would also be considered an acute triangle; yet, without that specific angle measurement, it cannot be classified as such.

Thus, an acute triangle is the definitive answer when identifying a triangle where all angles are acute, as it meets the criterion of having all angles smaller than 90 degrees.