<!DOCTYPE html>
<html>
<body>
<canvas id="myCanvas" width="300" height="150" style="border:1px solid #d3d3d3;">
Your browser does not support the HTML5 canvas tag.</canvas>
<p>Try to set the miterLimit to 4 (then, the miter length will exceed the miter limit), and when the lines meet it will be displayed as lineJoin="bevel".</p>
<script>
var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");
ctx.lineWidth = 10;
ctx.lineJoin = "miter";
ctx.miterLimit = 5;
ctx.moveTo(20, 20);
ctx.lineTo(50, 27);
ctx.lineTo(20, 34);
ctx.stroke();
</script>
</body>
</html>