Perimeter and Area

For the past few days we have been learning about P and A short for (Perimeter and Area) During these lessons I've come to understand how they work I know that you need to know your times tables, cm's or m's and also remembering that if i'm using area that no matter if I'm using cm's or m's  or  whatever that I need to remember to put 2 at the end of them  for example: cm2 but in perimeter I need to plus the four number for example: if I had a rectangle with 2 cm long and 5 cm wide so i'd go like this 5 + 2 + 5 + 2 = 14cm and in area i would times  it like this 5 x 2 = 10cm2 and that's what i've been doing so far and here's another example if you still don't get it.