Look at the triangle shown below. The measures of the angles are shown in the sketch

no this is a nonlinear negative

what is the answer?

check above link.

graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.