Sphere in a tetrahedron

Given the lengths of the edges of a tetrahedron calculate the radius of a sphere inscribed in that tetrahedron (i.e. a sphere tangent to all the faces). You can read more about a tetrehedron here - https://en.wikipedia.org/wiki/Tetrahedron Input An integer t, 1Output t lines, each consisting of a real number given with four digits decimal precision equal to the radius of a sphere inscribed in