So we know that the angles of a quadrilateral add up to 360, this fact will give us the base knowledge to come up with the equation to solve this problem.
We also know that angles diagonal from each other are equal because the lines are parallel.
First we need to find x
2(14x)+2(6x)=360
x=9
now that we know what x equals we can substitute it for 9
14x would be 14(9)
14x=126
6x would be 6(9)
6x=54
In order to check it, take the original equation 2(14x)+2(6x)=360 and substitute 14x for 126 and 6x for 54
