Edit in JSFiddle

.test1 {
    width: 0;
    height: 0;
    border-width: 0 200px 200px 0;
    border-style: solid;
    border-color: transparent transparent #eee transparent;
    border-right-color: rgba(238, 238, 238, 0);
}

.test1 {
    margin: 30px;
}
<div class="test1"></div>