JSFiddle - React, Tailwind, and code Playground

HTML

<div id="mainDiv">
  <div class="borderLeft">
    <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris suscipit quis est vel fringilla. Quisque eget tellus sed est vulputate varius. Quisque scelerisque lobortis molestie. Ut libero lorem, consequat quis commodo et, porttitor et sapien.
      Donec tristique purus eget nunc tincidunt ornare. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nulla consequat pellentesque pharetra. Donec imperdiet ex metus. Vestibulum nulla ligula, semper vel odio ut, ornare pellentesque arcu. Sed
      neque lectus, fermentum non ultricies id, sollicitudin eget turpis.</p>
  </div>
</div>

CSS

#mainDiv {
  height: 500px;
  width: 500px;
  position: relative;
  background: #3beadc;
  border-radius: 0 0 50% 0;
  border:10px solid black;
}

.borderLeft {
   height: 520px;
  width: 520px;
    border-radius: 0 0 50% 0;
  border:10px solid black;
  position: absolute;
  top: 0px;
  right: 10px;

}