Hey there!
All of the given angles of a triangle will always add up to 180 degrees. Therefore, our angle measures are 100, 40, and 40. There are 3 types of triangle classifications based on angles.
Acute: all three angles are less than 90 degrees.
Right: one angle is 90 degrees.
Obtuse: has an angle that is greater than 90 degrees.
As you can see, we have one angle that is greater than 90, which is 100.
Therefore, this is an obtuse triangle.
I hope this helps!
