I don't see a drawing of the quadrilaterals, so I don't know what the perimeter of quadrilateral P is. But whatever the perimeter of P is, Q will be 1/3 of that. Perimeter is a length, so even though it may pertain to a 2-dimensional object, it is still a 1-dimensional, linear measure. When two objects are similar (same shape, but scaled up or down by a scale factor), all corresponding linear measures have the same scale factor.
If you were asked about area or volume, that would be a different matter. In the case of area, you would square the scale factor, and in the case of volume, you would cube the scale factor.
An exponential growth function can be written in the form y = abx where a > 0 and b > 1. The graph will curve upward, as shown in the example of f(x) = 2x below. Notice that as x approaches negative infinity, the numbers become increasingly small.
