Question 1148528
3x + 6y = 180
2x + 10 + 40 + z = 180
x + y + z + (angle 6) = 180
6y = 40 + z


The first, second, and fourth equations are usable.


x + 2y = 60
2x + z = 130
6y - z = 40


Solving, we get (x, y, z) = (10, 25, 110).


Now we can substitute into the third equation:


10 + 25 + 110 + (angle 6) = 180


angle 6 = 35 degrees