AMC 12 2002b Problem 5

Let $v, w, x, y,$ and $z$ be the degree measures of the five angles of a pentagon. Suppose that $v < w < x < y < z$ and $v, w, x, y,$ and $z$ form an arithmetic sequence. Find the value of $x$.

$\mathrm{(A)}\ 72 \mathrm{(B)}\ 84 \mathrm{(C)}\ 90 \mathrm{(D)}\ 108 \mathrm{(E)}\ 120$