To alter the Line Location, click on one of the choices under the line location heading. The selection will appear in dark grey as a visual indicator of the currently active line location setting.
The example below shows what a Rectangle looks like when each Line Location choice is selected: Center, Outside, and Inside.
A line location change will be seen instantaneously when a stroke figure is selected. If no figures have been selected, the line join change will apply to all subsequently created stroke figures.