The perimeter of the square is 8 cm. From two such squares they made a rectangle. Find the area of this rectangle.

The perimeter is the sum of the lengths of all sides.
Therefore, if the perimeter of one such square is 8cm, then side 8: 4 (sides of the square) = 2
The width of the resulting rectangle will clearly be 2cm.
And the length will be side (2cm * 2 (sides of the square) = 4
So, we got a rectangle whose sides are 4cm and 2cm (if you can’t imagine a rectangle of squares in your head, it’s better to draw a picture);
Rectangle area = a * b
a = 4
b = 2
Spr = 4 * 2 = 8 cm