The answer is 12+3r because 4 times 3=12 then the 3r which you cannot add because they are no others variables that are r
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.
I'm pretty sure that it is 140. Hope I helped!
