Question

Classify following triangle into acute, obtuse, right triangle:
In $△ABC,\angle A={40}^o,\angle B={41}^o,\angle C={99}^o$

Answer 1

The given triangle has an obtuse angle $(\angle C=99°)$ and two angles are acute angles $\left(\angle A\text{and}\angle B\right)$. Hence the given triangle is an obtuse angle.