Classify the triangle? In other words, state the type of triangle we have here: right, acute or obtuse.
If the triangle is a right triangle, then 48^2+55^2=80^2 by the Pythagorean Theorem. Let's check that out: We get 5329 = 6400, which is false. So this triangle is not a right triangle.
For this to be an obtuse triangle, 48+55 would have to be greater than 80. That's not the case here. Thus, the triangle is ACUTE.