Measure the length and width of your area rug.
How to secure area rug on top of carpet.
Flip the area rug over.
This way is cheaper and more durable than the carpet to carpet pads.
Walk across it a few times to help push the cleats into the carpet.
Now you have secured your area rug.
If possible help hold the area rug in place by setting heavy furniture on top of it.
While you could attach the tape side directly onto your carpet to hold the rug in place when you would remove the rug later you would have tape residue left on your carpet.
Placing a nonslip pad under your area rug will help keep it in place and minimize the stretching that occurs when an area rug is on top of carpet.