技術標籤：csscsscss3

<style>
        .triangle1 {
            width: 0;
            height: 0;
            border-style: solid;
            border-width: 0 25px 40px 25px;
            border-color: transparent transparent red transparent;
        }
        .triangle2 {
            width: 0;
            height: 0;
            border-style: solid;
            border-width: 40px 25px 0 25px;
            border-color: red transparent transparent transparent;
        }
    </style>
    <div class="triangle1"></div>
	<div class="triangle2"></div>