Answer:
The Slope of a line formula is given by
m=y2 - y1/ x2 - x1
Now Form a triangle using the straight line(It'd be best if you choose known Points on the graph)
Picking points (1, 2) and (2, 5) connect these points and you'll have a small triangle.
x1 y1 x2 y2
Substituting into the formula
m=5-2/2-1
m=3.
