To classify the triangle based on its angles:
- An acute triangle has all angles measuring less than 90°.
- A right triangle has one angle measuring exactly 90°.
- An obtuse triangle has one angle measuring greater than 90°.
In this case, the angles are 46°, 51°, and 83°.
- All of these angles are less than 90°, which means the triangle is an acute triangle.
So the correct response is acute triangle.