Triangle Inequality for Complex Numbers/Corollary 3

Corollary to Triangle Inequality for Complex Numbers
Let $z_1, z_2 \in \C$ be complex numbers.

Let $\cmod z$ denote the modulus of $z$.

Then:
 * $\cmod {z_1 - z_2} \le \cmod {z_1} + \cmod {z_2}$

Proof
Let $w = -z^2$.

Then: