Recall that the formula for the length of an arc of circumference is given by the formula:
where is the radian form of central angle subtended , and R is the radius of the circumference. What is important is to have the angle given in radians for this formula to be valid.
In our case, the angle ( ) is already in radians, so we can apply the formula directly:
I would think (10,1) and (1,9) would make the most accurate line of best fit since it is surrounded by most points. Would you agree? Since the (10,0) may just be an anomaly plot.