First let's calculate the slope of the curve
A = (8,0)
B = (11,4)
A straight line parallel to that curve has the same slope
First of all, remember what the equation of a line is:
y = mx+b
Where:
m is the slope, and
b is the y-intercept
m = 4/3
Now, what about b, the y-intercept?
The equation of the line that passes through the point (4,5) with a slope of 4/3
Blue line is the new bike path
Red line is the railroad