A rectangle with side lengths of 10cm and 5cm was cut into two identical squares. Find the perimeter of each square.

To solve this problem, you first need to determine the side length of the resulting squares.
Since in order for 2 squares to be formed from a rectangle, it is necessary to cut it in half along the center of the longer side, we get.
10/2 = 5 cm. (The length of each side of the square.)

Further, in order to determine the perimeter of the formed squares, you should find the doubled sum of its sides.
In this case, we get:
P = 2 * (5 + 5) = 20 centimeters.

Since the squares are the same, their perimeter is also the same and equal to 20 centimeters.