【多选题】What of the following description about giving angular dimensions are correct?
A.
The boundary lines or the extents of them can be the extension lines of an angular dimension.
B.
The dimension line of an angular dimension is an arc with certain radius, and the carter of the arc is the vertex of the angle.
C.
The dimension figure of an angular dimension can be drawn horizontally or leftward.
D.
The dimension figures of an angular dimension can be placed in the breaks, above or at the sides of the extension lines, or above leader lines which are drawn start from dimension lines.