Which ipad fits into 8x10 case?

You can compare all models of iPad - and find their physical dimensions - here:

iPad - Compare Models - Apple

Many prefer to choose an iPad by its technical capabilities - rather than its ability to fit a specific designer case. For those that prefer to choose in this way, it is a relatively simple task to Google-search for cases suitable for an iPad model.

In that case, assuming 8x10 is in inches, I guess it would in fact fit a 9th Generation iPad or an 11" iPad Pro First generation or later or an iPad Air 3rd Generation or later, some with more room than others.

See the "Size and Weight" section in the following link.

click here ➜ Compare iPads - iPad 9th Gen, 11" iPad Pro, iPad Air - Apple.com

Exactly which case are you looking at because most iPad cases are specified by iPad model, generation, even screen size diagonally.

I've never seen them defined by specific dimensions like that. Its possible it may not be a case designed for any iPad at all.

Also, as mentioned you normally choose the iPad first based on your requirements and then look for a case based on the model you chose.

Fitted cases will be designed with an explicit model in mind. If the case doesn’t explicitly state that it is designed for a specific iPad, it is likely not suitable.

That said, some cases are more generic in their design - and try to hold the the tablet computer with elastic straps. While such cases may be cosmetically very attractive, the primary purpose of protecting a very expensive iPad may be severely compromised.

iPad sizes are generally described by their diagonal screen size, this being measured between diagonally opposite corners of the visible screen. The diagonal screen measurement has little relationship to the overall dimensions of the iPad - as bezels and chassis measurements differ between model generations.

Again iPad cases will specifically state what model they are meant for. If they are just mentioning dimensions, they are very very likely not for an iPad.

There should be no reason for you to have to figure out dimensions when searching for an iPad case.

Just state the model and generation in a case search, and it should return results suitable for that specific model of iPad.

Where are you searching for these cases exactly, that return dimensions rather than compatible models?