How do I set my office documents to 5x7 paper size

[Stuie]

I am trying to type a letter on 5x7 paper but I do not know how to set up the paper size on my laptop. I have not
done this before so I need some help.

[LeroyG]

More help on page format from LibreOffice Help.

[AdmFubar]

In the main menu look for the Format entry, Format/Page Style. In the dialog that opens click the Page tab.
All the page setting are there.

[CodingChimp]

When using LibreOffice Impress, the document size options are under:
“Slide” menu
“Properties” item
“Slide” tab

#resize-Impress slide deck
#Impress-slide-size