How to make this part?

Question

css

Please help me to make it up, according to the layout it is adjacent to the block on the right side, I don’t know how to make it up.
Here is a link to the picture.
my-files.ru/0difku

Answer 1

We look and apply a banal question: htmlbook.ru/blog/treugolniki-cherez-css

Answer 2

<div id="name"></div>

#name {
    width: 0;
    height: 0;
    border-left: 20px solid hsl(42.6, 100%, 55.5%);
    border-bottom: 77px solid #f000;
    border-top: 77px solid #f000;
}