Hello,
I assume that your quadrilateral is a parallelogram.
I've modified your drawing a little bit. As you can see (see attachment), the perimeter consists of:
x + x+2 + x + x+2 = 52
4x + 4 = 52
4x = 48
x = 12
Therefore the sides of the parallelogram are 12 cm and 14 cm long.
Hello, Jhevon, that was a near miss