For this type of problem the way to do it is..
1) add the inside of the triangle, in this case it is --> 132 + (2×+4) and then you set it equal to the number that's outside the triangle which is 112
2) and then you solve .... 132+4=136
3) your equation should look like ---> 2×+136=112
4) you subtract 136 from both sides
5) you get 2×= -24
6) divide 2 from both sides.. and you get ×=-12
that's if they are asking for the value of X
if they want to go further... you plug in the value of x in which we found was -12 into the angle above... I hope I helped.
