To make a polyline, select the Polyline tool from the Draw panel of the Home tab or use its command alias, PL. Start the polyline command, and you will notice many options on the command line, as shown in Figure 8.46:

Select the Halfwidth option from the command line, or type H, and press Enter. Now, the command line will prompt you to specify the starting halfwidth value. Type 1 and press Enter. The command line will again prompt you to specify the ending halfwidth value. Type 1 again and press Enter. Now, click on three points in the drawing area so that you end up with a triangle. Press Enter when you are done making the triangle with the polyline, and you will notice that the triangle is made with a thick line with a width of 2 units. In my example, the triangle looked like this:

In this case, the total width of the polyline is 2 units, as we specified the halfwidth value as 1 unit, which makes the full width 2 units. This is an example where you can use a polyline to make thick lines without using a solid Hatches pattern to fill the area. Another option on the polyline command is width, as shown in Figure 8.46. This width option also lets you make a similar polyline, but the only difference is that you need to specify the total width of the polyline, rather than the halfwidth.

Another interesting example of this polyline feature is explained here:

1. Start the polyline command and then select the Width option from the command line.
2. Now, specify 0 as the starting and end width of the polyline and make a polyline of length 5 unit towards the right side of the screen.
3. With the polyline command active once again, select the Width option from the command line, specify the starting width as 1 unit and the ending width as 0 units, and add the line again towards the right side, with a length of 2 units.
4. This time, you will end up with an arrow-shaped polyline, as shown in Figure 8.48, where the straight-line part is 5 units long and the thick part is 2 units long. Also, the arrowhead starts with a width of 1 unit and ends at a point as the ending width as 0 unit:

In this case, we ended up making this interesting shape without the use of multiple commands and as a result, we have a very simple geometry made with the polyline command.

Once you add width to the polyline, it tends to make other polylines with that same width. So, if you want to return to the normal polyline, select the polyline command, click the Width or Halfwidth option, and then change the starting and ending width to 0 units. When you make a polyline this time it will be made with the default thickness.