<div class="element"></div>

body {
	background-image: radial-gradient( circle 360px at 50% 50%,  rgba(54,96,172,1) 0%, rgba(46,53,89,1) 100.2% );
	display: flex;
	align-items: center;
	justify-content: center;
	height: 100vh;
	margin: 0;
}

.element {
	width: 0;
	height: 0;
	border: 50px solid transparent;
	border-bottom-color: #fff;
	border-left-color: #fff;
}