Construction Aid Circle Arc > Concentric to Circle (Construct Menu)

This command draws a Construction Aid circle arc which is concentric with another circle. The arc is determined by identifying the circle and entering the radius, start and end angles.

If a Construction Aid circle arc is to be drawn while working in isometric or dimetric view, then the command Construction Aid Ellipse Arc > Vector - Vector must be used, because the result on the page is elliptical not circular.

Any circle which exists independently or as part of another object can be identified as the reference object. This can also be the arc of a circle segment or a circle arc within a surface.

The radius of the Construction Aid arc can be entered by clicking the mouse anywhere in the drawing at a point through which the arc should run.

The Construction Aid arc's start angle can be entered by clicking the mouse anywhere in the drawing. The position of this point relative to the center determines the start angle.

The Construction Aid arc's end angle can be entered by clicking the mouse anywhere in the drawing. The position of this point relative to the center determines the end angle.

The resulting arc is affected by the current arc direction setting. This is set using the command Toggle Arc Direction (F2), with the F2 key or the button in the panel. If the arc direction is positive, then the arc is drawn in a mathematically positive direction (i.e. counterclockwise) from the start angle to the end angle. If the arc direction is negative, then the arc is drawn in a mathematically negative direction (i.e. clockwise) from the start angle to the end angle (see graphic).

The resulting arc is shown while it is being entered and changes immediately if the current arc direction is changed.

The arc direction settings of existing arcs are not affected by changes to the current arc direction. To change the arc direction of an existing arc, use the command Transform Object to > Invert.