利用CSS3画图
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<style>
#hei {
width: 100px;
height: 90px;
/* background-color: aqua; */
margin: auto;
position: relative;
}
//在hei的左右添加伪元数
#hei:before,
#hei:after {
content: "";
width: 50px;
height: 80px;
background-color: red;
position: absolute;
//border-radius 属性是一个简写属性，用于设置四个 border-*-radius 属性
border-radius: 25px 25px 0 0;
//先右旋转45度
transform: rotate(45deg);
//从那个点开始旋转
transform-origin: 100% 100%;
}
#hei::after {
left: 50px;
transform: rotate(-45deg);
transform-origin: 0 100%;
}
#sanjiao{
width: 0px;
border: 20px solid red;
//transparent透明
border-color: brown transparent transparent transparent;
transform: rotate(180deg);
}
</style>
<body>
<div id="hei">
</div>
<div id="sanjiao">
</div>
</body>
</htm
盒子模式
