When solving two equations using the graph method, the solutions are points where the two graph equations meet. This gives the values of x-coordinate and y-coordinate that satisfy the 2 equations.
The intersection of the two equation makes the solution.
Considering the diagram below the equations meet at (2,-6) and (-5, -13).
It’s hard to tell due to no labels, but these are your angles due to the equal angles theorem and a few other theorems. Hopefully with this image you can hopefully find your answer. You may need to add angles together depending on what you are looking for. And possible even figure out what angle measure would make a (180 degree) triangle. Hope this helped