[color=#999999]This activity belongs to the [i]GeoGebra book[/i] [url=https://www.geogebra.org/m/sw2cat9w]GeoGebra Principia[/url].[/color][br][br][br]A T-sphere is formed by the points in space that are T-equidistant from its center. It takes on the shape of a regular E-octahedron (which is not T-regular, as T-regular triangles do not exist) with its diagonals parallel to the axes. It can also be generated by T-rotating a T-circle around the horizontal or vertical diameter.[quote]The loci that appear in taxicab geometry invite us to ask: what does "something" need to have in order to be that "something"? What characterizes an object? For instance, is the E-sphere round because its points are equidistant from its center, or is it round due to the uniformity in the direction that Euclidean distance possesses? [/quote]

[color=#999999]Author of the construction of GeoGebra: [url=https://www.geogebra.org/u/rafael]Rafael Losada[/url].[/color]