If the base and height are multiplied by 6, then each side of the parallelogram is multiplied by 6. The overall effect is that the perimeter is multiplied by 6. This applies to any linear aspect of the parallelogram.
Consider the example of having a parallelogram with side lengths of: 1, 2, 1, 2
The perimeter is 1+2+1+2 = 6
If we scale each side by a factor of 6, then the new sides are: 6, 12, 6, 12
The new perimeter is 6+12+6+12 = 36 which is 6 times larger than the old perimeter
Answer: The old perimeter is multiplied by 6 to get the new perimeter