The length of an arc of the sector of angle θ° of a circle with radius R is

The length of an arc of the sector of angle θ°">θ° of a circle with radius R is

(a) $\frac{2 \pi R \theta}{180}$

(b) $\frac{2 \pi R \theta}{360}$

(c) $\frac{\pi R^{2} \theta}{180}$

(d) $\frac{\pi R^{2} \theta}{360}$