Centroid of a circular arc of radius \(R\) including angle \(2 \alpha\) can be given by:

(a) \(\bar{X}=\frac{R \sin \alpha}{\alpha} ; \bar{Y}=0\)

(b) \(\bar{X}=\frac{2 R \sin \alpha}{\alpha} ; \bar{Y}=0\)

(c) \(\bar{X}=\frac{R \sin 2 \alpha}{\alpha} ; \bar{Y}=0\)

(d) \(\bar{X}=\frac{R \sin 2 \alpha}{2 \alpha} ; \bar{Y}=0\)