To find the area all you have to do is mulitply the length by the width of the rectangle. So if your rectangle is 6.5 feet long and 2 feet wide: the area is 6.5 ft x 2 ft= 13 ft2. Notice the unit changes from feet (ft) to feet squared (ft2) when you mulitply numbers with the same unit. When you caluculate area the unit is always squared!
The perimeter of your rectangle is easy too. Since the opposite sides of a rectangle are equal to each other and you know the length of the long and short sides then you just add them together and multiply by 2. This is the same as adding each side of the rectangle together. 6.5 ft + 2 ft + 6.5 ft + 2 ft = 17 ft. Another way to think about perimeter is how far would you have to walk if you walked all the way around the rectangle. You simply count the number of feet of each side as shown above.