Adds a number of copies of a sketch or a solid, which are arranged on a circle, to the shape.
Plane  Only for solid type bodies. 
Quantity  The number of parts of the arrangement, including the original one. 
Radius  The radius of the circle, on which the copies will be arranged. 
Angle Range  Defines the range of the circle, in which the copies will be arranged. The angle between each element will be Range / (Quantity  1). 
Alignment  Defines the distribution of the elements in relation to the original element.

Original Angle  The angle of the circle center to the original shape pivot. Use this parameter to rotate the circle or rather move the center of the circle. 
Keep Orientation  If checked, all copies will keep the orientation of the original. Otherwise the elements will be rotated accordingly to their position on the circle. 
The circle center is defined by the shape pivot being a point on the circle, the Radius as the distance of the shape pivot to the circle center, and the Original Angle as the angle of the shape pivot on the circle. To move the center of the circle, adjust the Radius and the Original Angle.
Select a sketch or a solid.
Select Circular Array from ribbon menu.
If created from solid, select the plane on which the multiplied elements will be distributed.
Adjust parameters in the property panel or using the live tools.