Relationship

[Kerrill]

Hi,
     on Ancestry I have come up with a lady who has shared DNA 180cm across 10 segments, I believe through word of mouth many years ago that her grandfather is my grandmothers brother, but she believes that they were cousins is there anyway we could find out through the DNA side of things?

[brigidmac]

This is a useful tool for likelihood of cm matches

https://dnapainter.com/tools/sharedcmv4
 
If your grandparents were brothers you.d be second cousins.
That amount compares with my own second cousin
amount

modified  ,but I have third cousins at 160cm  and some half second cousins around the 200 mark .

[Kerrill]

Thanks very much brigidmac,
                                              forgot to say that Ancestry have us as 3rd to 4th cousin's, so she is probably right then.