Why an icosahedron?
A polyhedron is a many-sided 3-dimensional object. An icosahedron is a polyhedron with 20 equilateral triangular faces. Of the five Platonic polyhedra (all of which have equal faces in size and shape), the icosahedron most closely approximates a sphere. Fuller found that the best way to lay various polyhedra flat while keeping all the land masses unbroken was to use the icosahedron. With only two exceptions, all the breaks needed to lay the icosahedron flat occur completely within the oceans, and, therefore, keeps the division of land masses to a minimum. With minor adjustments to two triangular faces, Fuller’s Dymaxion Air-Ocean World Map provides us with a flat view of all the Earth’s land masses as unbroken islands in a single world ocean.
