How do you find the length of an arc in a circle?

To find the length of an arc in a circle, the correct formula involves the central angle of the arc expressed in degrees. The arc length can be calculated using the formula:

Arc length = (θ/360) × 2πr,

where θ is the measure of the central angle in degrees and r is the radius of the circle. This formula works by recognizing that the total circumference of the circle is 2πr, and the fraction of the circle represented by the arc is determined by the ratio of the central angle θ to the full angle of a circle, which is 360 degrees.

Thus, when you multiply the total circumference (2πr) by this fraction (θ/360), it gives you the actual distance along the arc. This is why option B is the correct choice; it accurately represents the proportional relationship between the length of the arc and the fraction of the circle that the arc occupies.

The other options do not correctly represent the relationship needed to find arc length based on the central angle and the full circle's circumference.