Answer:
x must be 14/4 = 7/2
Step-by-step explanation:
The sum of the three interior angles of a triangle must be 180 degrees.
Thus, in this particular case,
82 + 64 + 4x + 20 = 180, or
146 + 4x = 160, or
4x = 160 - 146 = 14
Then 4x = 14, and x must be 14/4 = 7/2
