AutoCAD 2019 - Creating a Circle from an ARC

By Martin Phelps  

At first glance this seems to be quite an easy task, all you need to do is draw a line from the “Centre” of the “Arc” to the end of one side of the “Arc”, as shown in Figure 1.

Figure 1. 

Now use the “Extend” command to extend the “Arc” to the “Line”, closing the gap and producing a “Circle”.

However, this does not work since an “Arc” cannot have an angle of 360 degrees, and by using the “Extend” command this is what AutoCAD is trying to do to the “Arc”.

If this method is tried a “No Entry” sign is displayed, not allowing the function to be carried out, as shown in Figure 2.

Figure 2.

So how do you create a “Circle” from an “Arc”?

Select the “Join” command, located in the “Modify” fly out panel as shown in Figure 3. 

Figure 3. 

Select the “Arc”, confirm by pressing “Enter”, either type in “L” and press enter to confirm, select “Close” from the command line, or right mouse click and select “Close” from the displayed menu options. 

The “Arc” is now converted into a “Circle”.