Okay so you have to get 180° because that’s the number you have to get off a triangle. so you have to add 57° and 88° together which is 145° and then you have to subtract 145° from 180° (180-145=35). so x should be 35°
Mx+b=y m is your slope which u can find by using two point see how far the x are and the y are then the y/x is your slope. Then he is your starting value so what y is when x= 0