Question

Two angles in a triangle are 30° and 35°. What type of angle is the other?

Answer 1

30°+ 35°+ x = 180°
65°+ x = 180°
x = 115°

The third angle is 115°. Because it is greater than 90° it is an obtuse angle.

Answer 2

The third angle is obtuse.
Since the shape has 3 sides, then the total measure of degrees is (n-2)180 = (3-2)180 = 180°.
So our equation would be
180° = 35° + 30° + x°
x = 115°
115 is greater than 90, so the angle is obtuse.