To determine the type of triangle based on its angle measurements, we can classify it as follows:
- Acute Triangle: All angles are less than 90 degrees.
- Right Triangle: One angle is exactly 90 degrees.
- Obtuse Triangle: One angle is greater than 90 degrees.
In this case, the angles of the triangle are 40 degrees, 81 degrees, and 59 degrees. All of these angles are less than 90 degrees. Therefore, the triangle is classified as an acute triangle.