Let ABC be a regular triangle with unit side length. On the side BC we construct two arcs with unit radius that intersect at point A1. Similarly we construct arcs on sides CA, AB, that intersect at points B1, C1, respectively. We flap up the three quasi-triangles BCA1, CAB1, ABC1, and form a quasi-tetrahedron. Determine the height of the quasi-tetrahedron.