How to organize a block with an internal arc?

Question

css

It is necessary to implement a div block with an inner arc, something like this:

I was able to generate this by clumsily poking at the dots using the cssplant.com/clip-path-generator service. However, the dots are not even.
Unfortunately, the search was not crowned with much success, who faced such tasks, please tell me the solution.

Answer 1

you can do it manually: tympanus.net/codrops/css_reference/clip-path here is the manual!

Answer 2

codepen.io/aliencash/pen/GoyZrG
Play around with the parameters yourself...