cannot format LibreOffice impress slide, all help appears to refer to non-existent menu item

Question

I simply want to change page dimensions. Every website I visit starts with the instruction

1. Click format
2. Select page

I can't get that far. I may not even understand what it means to "Click format" There is a format menu, but it does not have a page submenu. It has

Text
Spacing
Align
List
---
Styles
(Default Formatting)
---
Character...
Paragraph...
Bullets and Numbering...
---
Image
Object and Shape
Form
Shadow
---
Animation
(Interaction)
---
(Name)
(Description)
---
Align
Arrange
Flip
Rotate
Distribution...
Group
---
Convert

But it does not have page. So I don't know what do to. I've spent time hovering over icons in case the instruction "Click format" specifically refers to an icon I must click.

Answer 1

One must be careful to check whether answer is for LibreOffice apps in general, or specifically for LibreOffice impress. In certain support forum contexts the distinction is blurred.

Specifically for LibreOffice impress, it is not Page format but rather Slide Properties format.

Here is the a good answer from LibreOffice support, specifically addressing impress

https://ask.libreoffice.org/en/question/94648/setting-page-orientation-in-libreoffice-impress/