CSS Oval String Radius of a Triangle?

Question

i there a way to make the largest string of this triangle an oval string like in the picture? Thanks!

    #triangle-topleft {
      width: 0;
      height: 0;
      border-top: 50px solid red;
      border-right: 100px solid transparent;
    }
  

<div id='triangle-topleft'></div>

Expected:

Answer 1

You can use border-bottom-right-radius: 100% on a rectangle to achieve something like this.

#triangle-topleft {
  width: 100px;
  height: 50px;
  background-color: red;
  border-bottom-right-radius: 100%;
}

<div id="triangle-topleft"></div>