The given exterior angle and angle Y are supplementary angles and need to equal 180 degrees.
To find Y subtract the outside angle from 180:
Y = 180 - 124 = 56 degrees.
Now the 4 inside angles of the figure need to equal 360 degrees.
To find X Subtract the 3 known angles from 360:
X = 360 - 56 - 65 - 125 = 114 degrees.
The answer is C.
