CSS

make triangle using div

// css clip
<div id="triangle"></div>

#triangle {
	background-color: #003BDE;
	clip-path: polygon(50% 0, 100% 100%, 0 100%);
	width: 100px;
	height: 100px;
}

how to make a triangle in css

.triangle{
  border-left: 5px solid transparent;
  border-right: 5px solid transparent;
  border-bottom: 5px solid red;
  border-width:100px;
}