When an object moves in a circular/curved path, the line joining center of curvature and its current location rotates. Let this line make an angle theta with vertical or horizontal. If theta is increasing in anti-clockwise as the object moves, then angle of angular velocity is anti-clockwise. So angular velocity has the direction of increasing angle theta. It is also denoted by the direction perpendicular to plane of curve in which object moves. Point all four fingers of right hand in the direction of movement of object ie., curve, then thumb stretched points in direction of angular velocity. If object moves clockwise , then angular velocity is in direction of a line perpendiculr to plane of paper, going into the paper.
