我们可以通过改变边框的宽度和高度，实现三角形和梯形图案的呈现，具体操作如下：
<!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> <style> .box { width: 100px; height: 100px; border: 5px solid blue; } .triangle{ width: 0; height: 0; border-width: 100px; border-color: transparent transparent pink transparent; border-style: solid; /* 三角形 */ } .trapezoid{ width: 70px; height: 0px; border-width: 100px; border-color: transparent transparent green transparent; border-style: solid; /* 梯形 */ } </style> </head> <body> <div class="box"></div> <div class="triangle"></div> <div class="trapezoid"></div> </body> </html>
代码运行结果如下：
