为啥我把通过伪元素添加的两个三角形旋转72度时，五角星的顶角无法完全重合，调成72.5度时看起来是重合的

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来源：2-13 编程练习

慕姐5289795

2021-05-09 10:57:28

老师，帮我检查下有没有哪里有问题

问题描述：

还想问下为啥我把通过伪元素添加的两个三角形旋转72度时，五角星的顶角无法完全重合，调成72.5度时看起来是重合的？

相关代码：

<!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>星星和国旗</title>
    <style>
        .box {
            width: 600px;
            height: 400px;
            margin: 0 auto;
            background-color: red;
        }

        .box .star {
            width: 0;
            height: 0;
            border-left: 50px solid transparent;
            border-right: 50px solid transparent;
            border-top: 30px solid yellow;
            position: relative;
        }

        .box .star::before {
            content: '';
            width: 0;
            height: 0;
            border-left: 50px solid transparent;
            border-right: 50px solid transparent;
            border-top: 30px solid yellow;
            position: absolute;
            top: -30px;
            left: -50px;
            transform: rotate(-72.5deg);
        }

        .box .star::after {
            content: '';
            width: 0;
            height: 0;
            border-left: 50px solid transparent;
            border-right: 50px solid transparent;
            border-top: 30px solid yellow;
            position: absolute;
            top: -30px;
            left: -50px;
            transform: rotate(72.5deg);
        }

        .box .star.big {
            transform: translate(45px, 90px);
        }

        .box .star.little1 {
            transform: scale(0.4) translate(340px, -10px) rotate(30deg);
        }

        .box .star.little2 {
            transform: scale(0.4) translate(450px, 25px) rotate(45deg);
        }

        .box .star.little3 {
            transform: scale(0.4) translate(450px, 95px) rotate(5deg);
        }

        .box .star.little4 {
            transform: scale(0.4) translate(340px, 115px) rotate(40deg);
        }

    </style>
</head>

<body>
    <div class="box">
        <div class="star big"></div>
        <div class="star little1"></div>
        <div class="star little2"></div>
        <div class="star little3"></div>
        <div class="star little4"></div>
    </div>
</body>

</html>