Edit in JSFiddle

var contoh = document.getElementById('contoh'),
    context = contoh.getContext('2d');

context.beginPath();
context.moveTo(20,20);
context.lineTo(20,100);
context.lineTo(70,100);
context.strokeStyle="#E91E63"
context.stroke();
<canvas id="contoh" width="500" height="100">
  Teks ini akan ditampilkan jika browser kamu tidak mendukung "HTML5 Canvas".
</canvas>