AutoCAD Circle Command Tutorial
Drawing a circle in AutoCAD® is rather simple. The default method for drawing a circle is to specify a center point and a radius. You can also choose to create a circle based on a diameter, circumeference, or area. The Video AutoCAD circle tutorial will show you better how this is accomplished. The ellipse tutorial shows how to draw an ellipse that is not a symmetrical circle or the polygons tutorial shows how to draw other symmetrical shapes.
First, create a simple circle by a radius. Click the circle icon. The command line asks you to specify center point. Click in the drawing area to set a center point. The AutoCAD command line then asks you to specify radius of circle. Type a radius into the command line, about 5 ought to be enough, then press <Enter>. You now have a circle whose radius is 5.
Now create a circle by a specific diameter. Click the AutoCAD circle icon. Click in the drawing area to specify the center point. Look at the command line and see that it is asking you for a radius or diameter. The word diameter is in brackets. The letter "D" is capitalized to let you know that typing "d", then <Enter> will change this to diameter. Now type a diameter of about 10 and press <Enter>. You now have a circle in AutoCAD whose size is the same as the previous circle.
You may change these circles after they have been created through the properties box. Click the properties box icon (see AutoCAD Tutorials Intro 1) then select one of the circles. You may now type in a radius, diameter, area, or circumference for the circle and its size will change accordingly.