Virtually all significant relationships are shadowed by a third party - another person, a competing distraction, or even a memory. While clinicians almost always recognize notorious triangles for the curses that they are - extramarital affairs, for example, or feuds with the in-laws - many therapists continue to underestimate the extent to which different sorts of triangles complicate most people's lives. As ubiquitous as they can be destructive, relationship triangles are the focus of this illuminating new work, which provides a groundbreaking analysis of how triangles function and a hands-on guide to working with triangles in therapy with couples, families, and individuals. The authors show how and why triangles come into being, how to predict their evolving nature, and ways therapists can move from individual to dyad to triangle and back again to create a seamless web of therapy that greatly increases therapeutic flexibility and effectiveness.