windows - How to make cells perfect squares in Excel?

In Microsoft Excel,

I want to make the height of first three rows and first four columns (12 cells in the top left corner) such that these cells are squares. How can this be done?

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Surprisingly, Excel says:

Row height: 15
Column width: 8.43

So, these are not on the same scale.

Making both of them 8.43 gives me this:

Now, what should I do?