In a circle, if a chord is equal to the radius, it means that the chord subtends an angle of 60 degrees at the center of the circle. 

The length of an arc is given by the formula:

Arc length = \(r \times \theta\)

where \(r\) is the radius and \(\theta\) is the angle in radians. 

Since the angle is 60 degrees, we need to convert it to radians. We know that 180 degrees is equal to \(\pi\) radians. So, 60 degrees is equal to \(\frac{\pi}{3}\) radians.

Substituting these values into the formula, we get:

Arc length = \(r \times \frac{\pi}{3} = \frac{\pi r}{3}\)