Triquetra Frame

The triquetra (trefoil knot) is a geometric figure consisting of three mutually intersecting vesica piscis lens shapes. The central region common to all three lenses is a Reuleaux triangle. Also: In topology, a branch of mathematics, the trefoil knot is the simplest example of a nontrivial knot. The trefoil can be obtained by joining together the two loose ends of a common overhand knot, resulting in a knotted loop. As the simplest knot, the trefoil is fundamental to the study of mathematical knot theory, which has diverse applications in topology, geometry, physics, chemistry and magic. The trefoil knot is named after the three-leaf clover (or trefoil) plant. As the simplest nontrivial knot, the trefoil is a common motif in iconography and the visual arts. For example, the common form of the triquetra symbol is a trefoil, as are some versions of the Germanic Valknut.