Drawing arcs by BEC (Beginning-End-Center)

You can construct an arc by sequentially positioning three points (starting, end and center), as well as the radius of the arc and the angle between the two radii connecting the center with the starting and the end points of the arc.

Control points

An arc defined by a beginning, a center and an end has four control points: its starting and end points, the center point of the circle the arc belongs to, and a point that lies in the middle of the circumferential length of the arc. While you are drawing an arc by BEC, the following pointers appear:

About to draw the starting point of the arc.

About to draw the end point of the arc.

About to draw the center of the arc.

NOTE: The contextual edit bars, attributes and tabular pane presentation, as well as the procedures for modifying and repositioning of an arc are the same for all arc-drawing modes except for arc by BEH.

To draw an arc by BEC

Do any of the following:

On the Objects toolbar, click the Arc by BEC .
On the Objects menu, point to Arcs, and then click Arc by BEC.
Press CTRL+D+A+B+E.

(Optional) Snap the starting point of the arc to another object or point.
In the graphical area, click where you want to draw the starting point of the arc.
(Optional) Snap the end point of the arc that you are about to place, to another object or point.
Use the mouse to draw the end point of the arc.

HINT: At this point the program begins exploring the angle between the radii of the sector the arc belongs to. At each angle divisible by 45 degrees (45, 90, 135, 180, 225, and so on) a visual hint appears at the center of the sector, indicating the angle. This lets you easily choose a common angle value.

To finish the arc, do one of the following:

Snap the would-be center point of the circle the arc belongs to.
Point to where you want the center to be, and then click.
In the contextual edit bar, in Radius and Angle enter respective values, press ENTER, and then click anywhere in the graphical area.

NOTE: To switch the directions in which the arc is being constructed, before you draw the center point, press CTRL.