Centroid of a sector of a circular disc of radius \(r\) and included angle \(2 \alpha\) can be given as:

(a) \(\bar{X}=\frac{3 R}{2 \alpha} \sin \alpha ; \bar{Y}=0\)

(b) \(\bar{X}=\frac{2 R}{3 \alpha} \sin 2 \alpha ; \bar{Y}=0\)

(c) \(\bar{X}=\frac{2 R}{3 \alpha} \sin \alpha ; \bar{Y}=0\)

(d) \(\bar{X}=\frac{3 R}{2 \alpha} \sin 2 \alpha ; \bar{Y}=0\)