Triangulation Basics

Triangulation looks for three or more people who all share DNA with each other. When everyone in the group matches on the same segment, they likely inherited it from a common ancestor.

Choose one of your DNA matches—often a known cousin—as a reference. The tool finds other relatives who also match both you and that person. Each new match forms a separate triangle (for example you + cousin + match C). Results can be viewed as a list of groups or as a network graph.

Interpreting groups: check for surnames, locations or tree details shared across the matches. If several members mention the same family name or come from the same area, it hints at the ancestor connecting you. The network view helps see whether the cluster sits on your maternal or paternal side.

Common uses: triangulation helps identify unknown ancestors. By clustering matches who all connect through the same line, you can home in on a mystery grandparent or confirm a suspected branch. Only you and the relative you select can view the results; private matches remain anonymous.

Select – none – in the ancestor list to remove a tag.

Ready to try it? Head back to the triangulation tool.