怎样用html或css制作三角形

只设置border三个方向的值，另一个方向就会汇聚成一个点，就出现三角形了，希望对你有帮助，望采纳！

#triangle-left {

    width: 0

    height: 0

    border-top: 50px solid transparent

    border-right: 100px solid red

    border-bottom: 50px solid transparent

}

下面是个示例：

<div style="width:200pxheight:174px-webkit-clip-path: polygon(50% 0, 0 100%, 100% 100%)clip-path: polygon(50% 0, 0 100%, 100% 100%)text-align:centerline-height:300pxcolor:#fffbackground-color:red">等边三角形</div>

<div style="width:200pxheight:100px-webkit-clip-path: polygon(50% 0, 0 100%, 100% 100%)clip-path: polygon(50% 0, 0 100%, 100% 100%)text-align:centerline-height:175pxcolor:#fffbackground-color:red">等腰直角三角形</div>

<style>

.test:after {display:inline-block content:"^" transform:rotate(180deg) scale(1.4,0.8)}

</style>

<span class="test">服务</span>

---