Answer: Sometimes.
Explanation:
Acute triangles are triangles that have three acute angles (<90 degrees).
For instance, a triangle with angle measures of 45, 50, and 85 would be an acute triangle, as would a triangle with angle measures of 65, 55, and 60. Those two triangles would not be similar, as their side lengths and angles are different. However, a triangle with identical angle measures and different side lengths are similar, whether acute or obtuse.