An equilateral triangle ABC is inscribed in a circle with centre O. Dis a point on the minor are BC and $$\angle$$ CBD = $$40^{\circ}$$. Find the measure of $$\angle$$ BCD.

A

$$40^{\circ}$$

B

$$50^{\circ}$$

C

$$20^{\circ}$$

D

$$30^{\circ}$$