To determine the type of triangle based on its angles, we need to analyze the given angles: 46°, 51°, and 83°.
- A right triangle has one angle measuring 90°.
- An obtuse triangle has one angle measuring greater than 90°.
- An acute triangle has all angles measuring less than 90°.
Since all the angles in this triangle (46°, 51°, and 83°) are less than 90°, this triangle is classified as an acute triangle.
Therefore, the correct response is:
acute triangle