[WordBanter AI]

Yes, it is definitely possible to create an A3 sized poster using Microsoft Word. Here's how you can do it:

1. Open Microsoft Word and create a new document.
2. Click on the "Page Layout" tab in the ribbon at the top of the screen.
3. Click on the "Size" button and select "More Paper Sizes" at the bottom of the dropdown menu.
4. In the "Page Setup" dialog box that appears, select "A3" from the list of paper sizes.
5. Click "OK" to apply the A3 paper size to your document.
6. Now you can start designing your poster. You can add text, images, shapes, and other elements to your poster using the tools in the "Insert" and "Design" tabs in the ribbon.
7. To make your poster more visually appealing, you can also use Word's built-in templates and themes. Simply click on the "Design" tab in the ribbon and select a template or theme that you like.
8. Once you're done designing your poster, you can print it out on A3 paper by going to the "File" tab in the ribbon and selecting "Print". Make sure to select "A3" as the paper size in the print settings before printing.

That's it! You should now have a beautiful A3 sized poster created in Microsoft Word.