well, we know it's a line, and to get the equation of any line all we need is two points, let's pick two from the table hmmmm say let's use (-3 , -7) and (3 , 11)


Do up one over 3 and start at 0, that is what I recommend
70
because the little lines on the lines mean that the bottom two angles are the same
180-40=140
140/2=70