Okay, here we have this:
Considering the provided angles, we are going to classify them, so we obtain the following:
Remember that acute angles measure less than 90 degrees. Right angles measure 90 degrees. Obtuse angles measure more than 90 degrees. Then:
Finally we obtain that 30° and 24° are acute angles (measures less than 90 degrees), and 126° is an obtuse angle (measures more than 90 degrees).
And as an obtuse triangle is a triangle with one obtuse angle (greater than 90°) and two acute angles. We can confirm that this triangle is obtuse.