如何用css画三角形

1、
#triangle02{ ???width: 0; ???height: 0; ???border-top: 50px solid blue; ???border-right: 50px solid red; ???border-bottom: 50px solid green; ???border-left: 50px solid yellow;
 }

2、

#triangle03{ ???width: 0; ???height: 0; ???border: 50px solid transparent; ???border-top: 50px solid blue; ???}#triangle04{ ???width: 0; ???height: 0; ???border: 50px solid transparent; ???border-right: 50px solid red; ???}#triangle05{ ???width: 0; ???height: 0; ???border: 50px solid transparent; ???border-bottom: 50px solid green; ???}#triangle06{ ???width: 0; ???height: 0; ???border: 50px solid transparent; ???border-left: 50px solid yellow; ???}