arithmetic
posted by patrice on .
picture 12960000cm area. frame 5cm wide. perimeter of frame/

Your area should be in cm^2, not cm. Did you omit a decimal point in the area?
You cannot determine the perimeter of the picture OR the frame unless the length/width ratio of the picture is known.
If the picture is a square, the length of a side is 36 meters! I have never seen a picture that large outside of Times Square. A 5 cm border would not make much difference.