If any of the angles are over 90 degrees, the triangle is classified as obtuse, if it's exactly 90 it's classified as a right triangle, and if all the angles are below 90 it is considered an acute triangle.
In this case you have 2 angles, 42 and 48, which seems to make the triangle acute. However, if you add them together and subtract from 180 (to find the third angle), you can find that the third angle is indeed 90 degrees, making it a right triangle.
