Use CSS to make a triangle

Use CSS to make a triangle

 
<!--do not set width-to-height conversion inline block edges are set to widths -<div class= "triangle" > Triangle review <span></span></div>/ * Relative positioning * /. Triangle {position:relative;        }/* Absolute Positioning */. Triangle span {Position:absolute;top:5px;display:inline-block;/* Inline block * /width:0; height:0;border-width:5px;   /* Edge color settings transparent the right-to-left change order on the transparent order to get a positive triangle line at different angles */border-color:transparent red transparent transparent;          / * Edge style set to solid line * /Border-style:solid solid solid solid;        }

#triangle-topleft {    width:0;    height:0;    border-top:100px solid red;    border-right:100px solid Transparent;}

　　

#triangle-topright {    width:0;    height:0;    border-top:100px solid red;    border-left:100px solid Transparent; }

　　

#triangle-bottomleft {    width:0;    height:0;    border-bottom:100px solid red;    border-right:100px solid Transparent;}

　　

#triangle-bottomright {    width:0;    height:0;    border-bottom:100px solid red;    border-left:100px solid Transparent;}

　　

Use CSS to make a triangle