Is this a regular polygon?

If $y=0$ , then $x=\dfrac{2018}{3}$

If $y=x$ , then $x=\dfrac{2018}{4}$

This is an octagon by symmetry, so let

$a=\dfrac{2018}{3}$

$b=\dfrac{2018}{4}$

The area of the octagon can be computed as follows

$Area = 8\cdot\dfrac{1}{2}b(a-b)+4b^2=1347441.3333...$

This is not a regular octagon