The child of your great aunt and great uncle is the first cousin of one of your parents and your first cousin, once removed.
Great great aunt/uncle. To your niece, you are the aunt/uncle, to her child you would be the great aunt/uncle. So you would then be the great great aunt/uncle of her child's child (her grandson)
Your uncle is your child's great uncle and your grandchild's great great uncle. Your grandson is your uncles great great nephew.
Your great uncle's child would be your second cousin. I think technically it is your first cousin, once removed! Second cousins, are cousins of cousins.
Your aunt's great uncle's father is her great grandfather, or is not related to her at all if the great uncle married a sister of her grandfather).He would then be your great great grandfather - or not related to you at all.
Your great uncle, the man who married your great aunt, has a daughter from a previous marriage. Unless your great aunt adopted her, that daughter is not related to you at all, and her child is certainly not related to your child. Of course if the great aunt and great uncle married while the daughter was very young, she may have been treated as a member of the family by everyone, so she would have been treated as if she were your parent's first cousin and your first cousin, once removed. In that case, you might choose to treat her daughter as if she were your second cousin, and her child as if she were your child's third cousin.
Your daughter would b related to her uncles child because they would b cousins
Your grandmother's nephew would be your parent's first cousin. They would be your first cousin once removed. Since the child of your cousin is a generation away from you they are the once removed.
Your grandfather's brother is your great uncle. The wife of your great uncle is your great aunt.
You and the granddaughter of your grandmother's brothers, and sisters, are first cousins.
It depends! For example, are you the uncle's child? That would make you and your wife first cousins. But you are not related to your wife's uncle if your only link to him is by marriage to her.
If your sister-in-law is still married to your brother and her daughter is the biological child of your brother you would be the child's great aunt or great uncle. If your sister-in-law is the sister of your husband, her daughter's baby is your great niece or great nephew, and you are the baby's great aunt or great uncle.
If your great great uncle (the brother of your great grandparent) had a great great granddaughter, you would be third cousins, once removed.