To solve for the value of x, you can simply add all of the values and expressions together and make it equal to 180 degrees, since the sum of all angles in a triangle add up to this amount.
Then we can solve for X, by algebra.
For the solid line it is (0,-3), (0,3), (-3,4)
for the dotted line it is (-1,-1), (-3,-2), (-3,2)
hope this helps don't know for sure though if its right i just did the best i could do.
1) angle 2 = angle 4
115 = 3x + 16
115 - 16 = 3x
99 = 3x
x = 33
2) angle 2 + angle 5 = 180 degrees
115 + angle 5 = 180
angle 5 = 180 - 115
angle 5 = 65 degrees
3) Angle 1 is equal to 120 degrees
