If you right click the polygon tool on the right you will find "Shaded Polygon (Angle by edge)"

Use that tool, and click the edge you want to align the fill with.

This will also cause the polygon to be shaded like a pitched roof. You can get rid of the shading but keep the fill alignment by typing EDITSHADING and hitting enter. Check the command line. It will ask you for the entity to edit. Click your polygon and a dialog will pop up. Don't be put off by all the controls. The only thing you need to do there is check the little box called "Shade Only Copy", and OK.

Once you have done that you should be ok.

After all the requests I had here and on the FB Group page I've done a set of 40 seal designs that I hope will include most of the things people asked for. There are a lot of others - the alphabet and the Futhark runes, as well as a set of blank seals.

Sorry about the red on red. It's the easiest way to make them really difficult to steal on a public forum ;)

It's not an ordinary copy paste operation. I'm sorry. I keep forgetting to explain properly because I'm so used to doing it myself.

If you right click the Sheets and Effects button on the left you will see Copy to Sheet in the right click menu. Use that, and you can copy the floor shape directly onto the WALLS sheet. You then need to hide everything but the WALLS sheet and change the properties.

If you hide all but the floor sheet you can then copy the floor you have drawn onto the walls sheet. Then hide all but the walls sheet and use the Change Properties button to change the fill and line width of the ex-floor. Giving the polygon a line width will make it into a wall around the same shape.

Make sure you also change the layer to WALLS as well as the sheet, and you will be able to cut doors through the walls with the cutting symbols.

Its TRACED, by the way. A newer and better version of the tool.

Before you use it make sure you have the correct sheet, layer and fill style selected as active. It's not a disaster if you didn't do that because you can use Change Properties to put things right again. It just makes things easier and faster.