div {

       position: relative;

        width: 28px;

        height: 32px;

        padding: 0;

        border: none;

}

​

div:after {

            content: '';

            position: absolute;

            width: 0;

            height: 0;

            border-top: 15px solid transparent;

            border-bottom: 15px solid transparent;

            border-right: 15px solid black;

}