A curve consisting of two mirror-reversed intersecting crescents (lunes). This curve can be traced unicursally.
The region common to both crescents is a lens.
Mohammed Sign
See also
Arc, Circle-Circle Intersection, Lens, Lune, Unicursal CircuitExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Mohammed Sign." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/MohammedSign.html