What is the edge length of a face-centered cubic unit cell made up of atoms having a radius of 139 pm?

In Chemistry, (Diagonal of the face of a face-centered cubic unit cell) = (Radius of an atom) × 4
In Trigonometry, (Diagonal of the face of a cube) = (Edge length) × √2

Hence, (Radius of an atom) × 4 = (Edge length) × √2
(139 pm) × 4 = (Edge length) × √2
Edge length = (139 pm) × 4 / √2 = 393 pm