Could anyone gimmie any clues with this please ?

By writing z + 2 + i = (z + 2i) + (2-i)

prove that $\displaystyle \sqrt {5} -2 \le $ $\displaystyle |z + 2 + i|$$\displaystyle \le \sqrt {5} +2$

for z being in A where A= 1$\displaystyle \le |z+2i| \le 2 $