That's Odd

An isosceles triangle can have its angles as $91,44.5,44.5$
A scalene triangle can have its angles as $91,10, 79$
A right angled triangle cannot have one of its angles as ${91}^°$ because one of its remaing angles would be ${90}^°$ , and $90 + 91 = 181 > 180$ .

So, the answer is $\color{#3D99F6}{\boxed{\text{Right angled triangle}}}$ .

In a right triangle, the highest measure is 90 degrees. That means that the two other angles are acute because the sum of the interior angles of a triangle is 180 degrees.