If we the area of the deck theyhave is 6x8=48^2feet
Now if we twice their dimension so they will be 12 and 16 respectively
Now the area is 12x16= 192^feet
This area is 4 times the prevoius area
Now if we want to double the original area for that we need to double only one dimension either width or length
Is we double 6 feet to 12 feet then area would be 12x8=96^feet
Same with another dimension if we double it 8x2=16
So area wouldbe 16x6=96^feet