Your grandfather's 3rd great grand uncle (or great-great-great-great uncle) is the brother of your 5th great-grandparent (or great-great-great-great-great grandparent).
He is therefore your 6th great grand uncle (or great-great-great-great-great-great-great uncle)
She will be your aunty
Two people whose grandfathers were brothers are second cousins to each other.
Your grandfather's great nephew is your second cousin.
She would be your great grandmother
Your grandfather's cousin is your cousin twice removed. Her husband has no direct relationship to you.
He would be your great-great uncle.
Most likely they would not be related to you
i think ALL YOU HALF NOT HALF &^what is that
The correct possessive form of "grandfathers" is "grandfathers'".
Your grandfathers' sisters' grandchildren are your second cousins.
If the grandfathers were 1st cousins, the grandchildren of each grandfather are 3rd cousins to each other.
Your husband's third cousin is just considered your third cousin through marriage.