Hi How i can i create an A1 size file in pages? Need to make a poster for school

Launch Pages. On the File menu, select Page Setup… . For Paper Size: choose Manage Custom Sizes… Click the + symbol to add a new Paper Size. Call it A1. Fill in the appropriate fields on the right of this panel, and then click OK. Click OK on the drop down Page Setup sheet. If you are uncertain about the A1 paper size, see the ISO paper size table in the Wikipedia Paper Size. Do you have a printer that can handle this larger A1 page size?

Back in Pages (assuming v5 here), select Document from the Toolbar. In the Document panel, change your default paper size to the new A1 that you just created. You will likely want to work on this larger document size in an external monitor, or via projector on a white screen or wall.

Menu > File > Page Setup > Paper Size > Manage Custom Size (at bottom) > + > rename as A1 > Paper Size: 840/594mm > Non-Printable Area: User Defined Top/left etc > 0/0/0/0 > OK

Peter