It has 4 sides.
You know how to do this, right..?
That's what the perimeter is for regular poligons too anon.
In a square it's 4 times a side because it has 4 sides, so it's just side + side + side + side, which is the same as side * 4
Like I am actually wondering if it can possibly so simple myself
Haha i asked myself the same and checked here : https://www.sophia.org/tutorials/perimeter-of-irregular-polygons--4
(quizz confirmed it but it's random).
I agree the question it's way too easy ;)
But why would it be different from regular polygons.. no reason really.