The perimeter of a figure is the distance around the outside of the figure. To find the perimeter of this figure, we need to add the lengths of all sides. This is:
P = A + B + C + D
P = x² + 4x + 8 + 2x² + x
P = 3x² + 5x + 8
The perimeter is 3x² + 5x + 8.