Not flat shapes like circles and squares, but solid shapes like cubes and cones ... GIRL 1: Now the next shape is a sphere. Try to make yourself into a sphere – a big ball!

A ring or sphere could, apparently, be stable if surrounded by the right sizes and gravities of other stars.

The nine chapters deal respectively with preliminary ideas, trihedral angles, skew quadrilaterals, tetrahedra, transversals, oblique cones, spheres, inversion, and recent geometry of the tetrahedron.

The Earth's inner core, long considered a solid and stable sphere, may be quite different ... causing changes in shape. These disturbances could also explain the gradual slowdown in the rotation ...

[DaveMakesStuff] demonstrates a great technique for 3D printing a sphere; a troublesome shape for filament-based ... at a higher temperature to ensure solid bonding between each layer.