D sqrt 53 approx 728 d 53. That is the exercise will not explicitly state that. In simple words the distance that runs through the curved line of the circle making up the arc is known as the arc length.
Displaystyle Delta sigma 2arcsin frac C 2.
As a special case of the distance formula suppose we want to know the distance of a point xy to the origin. In other words the equation of a circle gives the radius of the circle in terms. Suppose youre given the two points 2 1 and 1 5 and they want you to find out how far apart they are. The great circle distance is proportional to the central angle.