First lets fine the corner where 114° is. There are two angles laying on a straight line. A straight line is equal to 180°. So we can subtract to find that angle.
180 - 114 = 66°
We already know that the other two angles are the same. A triangle is equal to 180° total. Lets use each answer choice and see which one is correct.
66 + 66 + 66 = 198° WRONG
66 + 33 + 33 = 132° WRONG
66 + 114 + 114 = 294° WRONG
66 + 57 + 57 = 180° CORRECT
Therefore, the correct answer is option D.
Best of Luck!