Is 4/12 greater than 4/6

4/12 is not greater than 4/6.
You can determine this by finding the least common denominator, which would be 12. Since 4/12 is already converted, you would only have to change 4/6. 
4 x 2 = 8
6 x 2 = 12 (common denominator)
The new fraction would be 8/12.
4/12 is less than 8/12.
Hope this helped :)

Byou start by adding them all and setting them equal to 180 since that is half of the total degrees in a circle.(2x+8) + (3x-14) + (3x-14) = 1808x-20 = 1808x = 200x = 25