The brother of your great great grandfather is your great great grand uncle, or, as some would say, your great great great uncle.
The brother of your great great grandfather would be your great great granduncle.
The children of your great grandfather's brother are your grandparent's first cousins, and your first cousins twice removed.
Yes, you and your great grandfather's brother's daughters are all descended from your great-great grandparents. Your great grandfather's brother is your great great uncle. His daughters are your grandfather's first cousins and your first cousins, twice removed.
If your great great grandmother and your husband's grandfather were brother and sister then you and your husband are second cousins, twice removed.
Your father's brother is your uncle. Your Grandfather's brother is your great uncle. Your Great Grandfather's brother is your great great uncle.
Your great great great grandfather's brother is your great great great great uncle. You are his great great great great niece or great great great great nephew.
Yes, you and the daughter of your great grandfather share a common ancestor in your great great grandparent. A shared ancestor makes you related. The daughter of your great grandfather's brother is your grandfather's (or grandmother's) first cousin. Therefore she is your first cousin, twice removed.
If your great great grandfather was the brother of someone else's great great grandfather then you and that other person are fourth (4th) cousins.
A great uncle is the brother of the great nephew's grandfather or grandmother.
Your great grandfather's brother is your great great uncle.
You are not related to the mother-in-law of any great uncle.
Your grandfather's brother is your great uncle
Your grandfather's brother is your great uncle.