Question

One angle in a triangle measures 120°. Which of the following could not be one of the other angle measures?

20°

33°

45°

73°

Answer 1

That would be 73 degrees. 

Answer 2

73 BECAUSE there are 180 degrees in a triangle when all the angles are added together. If one angle is 120 then the other angles must add up to 60 (180-120=60). It can't be 73 because then that means there would be no other angle and there has to be 3 angles in a triangle.