</canvas>
</div>
<script>
window.onload = function(){
var canvas = document.getElementById("canvas");
canvas.width = 800;
canvas.height = 600;
var context = canvas.getContext("2d");
context.beginPath();
context.moveTo(100,100);
context.lineTo(300,300);
context.lineTo(100,500);
context.lineJoin = "miter";
context.miterLimit = 10;
context.lineWidth = 5;
context.strokeStyle = "red";
context.stroke();
context.beginPath();
context.moveTo(300,200);
context.lineTo(500,300);
context.lineTo(300,400);
context.lineJoin = "miter";
context.miterLimit = 10;
context.lineWidth = 5;
context.strokeStyle = "blue";
context.stroke();
context.beginPath();
context.moveTo(500,290);
context.lineTo(700,300);
context.lineTo(500,310);