- Phecda (stars.astro.illinois.edu)
PHECDA (Gamma Ursae Majoris). Few figures in the sky move us more than the Big Dipper, its seven bright stars laid out in a long bent row that the British call the Plough. All but one of its stars are second magnitude, though Phecda, the third one in from the end of the bowl, and southernmost of the bowl stars, is just on the edge of third (2.44).
- Archimedean solid (Wikipedia)
In geometry, an Archimedean solid is one of 13 convex polyhedra whose faces are regular polygons and whose vertices are all symmetric to each other. They were first enumerated by Archimedes. They belong to the class of convex uniform polyhedra, the convex polyhedra with regular faces and symmetric vertices, which is divided into the Archimedean solids, the five Platonic solids (each with only one type of polygon face), and the two infinite families of prisms and antiprisms. The pseudorhombicuboctahedron is an extra polyhedron with regular faces and congruent vertices, but it is not generally counted as an Archimedean solid because it is not vertex-transitive. An even larger class than the convex uniform polyhedra is the Johnson solids, whose regular polygonal faces do not need to meet in identical vertices.