Answer: 18.5 cm
Explanation:
The diagonals of a rhombus are perpendicular bisectors so we can use the Pythagorean Theorem to find the side length of the rhombus. Remember that the sides of a rhombus are congruent (equal) so if we find the length of one side, we have found the lengths of all of the sides.

So, each side of the rhombus is 18.5 cm.