Answer
$$573^\circ, -147^\circ$$
Work Step by Step
Angles coterminal to angle $\theta$ are given by $\theta \pm n\times360^\circ$ where n is an integer.
Therefore, an angle coterminal with $213^\circ$ that is positive is
$$213^\circ + (1)360^\circ = 573^\circ$$
and an angle coterminal with $213^\circ$ that is negative is
$$213^\circ - (1)360^\circ = -147^\circ$$
