CSS 实现三角形

.triangle{
width: 0;
height: 0;
border-top: 50px solid black;
border-right: 50px solid transparent;
border-bottom: 50px solid transparent;
border-left: 50px solid transparent;
}
/*下面代码更加简洁*/
.triangle{
width: 0;
height: 0;
border: 50px solid transparent;
border-top-color: black ;
}