There are four orthorhombic Bravais lattices but only two tetragonal Bravais lattices.
(a) Show that a base-centered (C) tetragonal lattice is equivalent to a primitive (P) tetragonal lattice.
(b) Show that a face-centered (F) tetragonal lattice is equivalent to a body-centered (I) tetragonal lattice.


Reference: https://lampx.tugraz.at/~hadley/ss1/problems/tetragonal/Q.php