Circular motion

A particle of mass $m=$   g moves in a circle of radius $R=$  cm. The center of the circle is at position $x_0=$  cm, $y_0=$  cm. At time $t=$  s, the $x$-component of the position vector that points from the origin to the particle is $r_x=$  cm. What is the $y$-component of the position vector at this time?

$r_y = $ [cm]