<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="Generator" content="EditPlus®">
<meta name="Author" content="">
<meta name="Keywords" content="">
<meta name="Description" content="">
<title>Document</title>
</head>
<body>
<canvas id="canvas" width="500" height="500" style="background-color: yellow;"></canvas>
<script>
var c=document.getElementById("canvas");
var cxt=c.getContext("2d");
cxt.beginPath();
cxt.moveTo(250,50);
cxt.lineTo(200,200);
cxt.lineTo(300,300);
cxt.closePath();//填充或闭合 需要先闭合路径才能画
//空心三角形
cxt.strokeStyle="red";
cxt.stroke();
//实心三角形
cxt.beginPath();
cxt.moveTo(350,50);
cxt.lineTo(300,200);
cxt.lineTo(400,300);
cxt.closePath();
cxt.fill();
</script>
</body>
</html>
