Round rectangle in rectangle - how to detect coordinates in corners that are outside of round rectangle?

Question

I am struggling to find a way to solve this issue.

I am getting this picture 306px x 620px

It's an image with a rounded rectangle. In order to make the rounded rectangle only clickable I set border-radius: 80px; and this works.

Now I am trying to write a smart way in which I can test it and detect if (x, y) position of click (like on this image)

is actually outside of the rounded rectangle parameters

I had a similar idea like this https://www.jsparling.com/using-rectangles-to-fill-the-area-outside-of-a-circle/ but I want to check if there is some smart way to detect if (x, y) is outside of this rounded rectangle

Initially, I posted on https://math.stackexchange.com/ but they mention that is better to ask here.

Any help/idea would be appreciated.

---

Edit 1

Maybe more information: Left, Top of the rectangle is 0,0

---

Edit 2

Reproducible environment https://stackblitz.com/edit/angular-qvf3ue?file=src%2Fapp%2Fapp.component.ts

---

Edit 3

Just to clarify those are the things I know

    const height = 620;
    const width = 306;

And I know that border-radius: 80px; would prevent from clicking outside of this rounded rectangle (those small parts)

I am trying to write a test where I can check if the coordinate is not inside rounded rectangle area

---

Update - result

Thanks to both @Yves Daoust and @MBo

Since @MBo answered first with the correct answer I will mark his answer as correct.

If someone is interested in implementation - check it out

https://stackblitz.com/edit/angular-b4nwrd