var ctx = document.querySelector('#c').getContext('2d');
ctx.lineWidth = 20;
ctx.lineCap = 'square';
ctx.lineJoin = 'round';
ctx.strokeStyle = 'rgb(247, 63, 20)';
ctx.beginPath();
ctx.moveTo(15,15);
ctx.lineTo(163,140);
ctx.lineTo(203, 140);
ctx.lineTo(351, 15);
ctx.stroke();
ctx.closePath();
<canvas id=c width=366 height=250></canvas>
canvas {border: 1px solid #ccc;background:#eee}