on Memory Space

Hello Gang !
Say,
stMyStructure is structure
s1 is string
s2 is int
s3 is boolean
...
...
...
End

Now Does this stMyStructure Occupy Memory space ?? How to find it ??

After initiating the variable
stRec is stMyStructure
stArr is Array of Structure

Now (I haven't Stored Any value to the Variable yet), Does these Variables stRec and stArr occupy Space in Memory ?? How to find it how much is occupied ??

And Now After Storing Values to the Variables stRec and stArr how Much Space would be Occupied in Memory ?? How to find it ??
Thanks !!