So, now that you know what an inscribed and a circumscribed polygon are, we are ready to make our first polygon. In this case, I will make a pentagon, which is a polygon with five sides, and I will use a polygon inscribed in a circle:

1. Select the Polygon tool from the Draw panel of the Home tab, or type POL and press Enter.
2. The command line will now prompt you to specify the number of sides of the polygon. Type 5 and press Enter.
3. Now, the command line will prompt you to specify the center of the circle. Click on a point in the drawing to specify the center.
4. Now, the command line will prompt you to specify the type of polygon: Inscribed in circle or Circumscribed about circle:

5. Select Inscribed in circle for this case.
6. Now, the command line will prompt you to specify the radius of the circle. Enter 5 as the radius and press the Enter key.

You will notice that an inscribed polygon with a radius of 5 units will be rendered. In this case, the radius of the polygon is the radius of the inscribed circle that this polygon is made in.

You can use a similar process to make a polygon that is circumscribed about the circle. Although these two options may seem like the only options for making a polygon in AutoCAD, its not always possible to have the radius of inscribed or circumscribed circles. If you only have the side length of the polygon, then you can use this next method to make a polygon using the side length.

In this example, I will make a hexagon with the length of its sides as 6 units:

1. Start the Polygon command from the Draw panel or use its POL command. 
2. Now, the command line will prompt you to specify the number of sides. Type 6 and press Enter.
3. Now, the command line will prompt you to select the center of the polygon, but in this case, select the Edge option from the command line:

4. Now, specify the first point of the edge by clicking anywhere in the drawing area.
5. You will notice that the cursor will now follow the edge of your polygon. Simply click on the second point to make a polygon of a required length, or specify the length in the command line and press Enter:

A polygon with the required edge length will be made. In this case, you were not required to specify the inscribed or circumscribed circle as the reference.

Now that we know about some of the basic draw tools that make a drawing, let's move on to learning about a few of the basic modify tools.