Answer:
x = 43
Explanation:
Since it says at the bottom that the sum of angle measures is 360° that means that you can dd up all the angles and it will equal 360.
Set up an equation
(3x) + (2x) + (x + 12) + (2x + 4) = 360
Then add them all together.
5x + (3x + 16) = 360
8x + 16 = 360
Subtract 16 from both sides to get 8x alone.
8x = 344
Then divide both sides by 8 to get x