Answer:
The perimeter is doubled.
Explanation:
Let's pretend we have a triangle with side measurements p,q, and r.
The perimeter will be the sum of the side measurements of this triangle which is p+q+r.
If we decide to dilate the figure by a factor of 2, then we are multiply each side by 2. So the perimeter of the new triangle becomes 2p+2q+2r.
Factoring this gives us 2(p+q+r). The perimeter has doubled.
The same thing would happen if we look at a quadrilateral. There would be 4 measurements multiplied by 2 and you would factor out the 2 giving you 2(old perimeter) for the new perimeter of the dilated shape.