Creating a Tab shape with CSS or SVG

Question

Does anyone have an idea how to make this tab like shape :

Answer 1

Here is figure:

Setting the border of an after element so that it cancels out the top part of the shape :)

.box {
  position: relative;
  background-color: tomato;
  width: 300px;
  height: 200px;
}
.box:before {
  content:"";
  position: absolute;
  right: 0;
  width: 100px;
  border-bottom: 15px solid transparent;
  border-left: 15px solid transparent;
  border-top: 15px solid white;
}
.box span {
  
}

Here you get a nice folder like figure :D