<script> window.onload = function() { var canvas = document.getElementById('quadro'); var ctx = canvas.getContext('2d'); ctx.beginPath(); ctx.moveTo(20,50); ctx.strokeStyle = '#f00'; ctx.arcTo(100, 50, 100, 130, 80); ctx.stroke(); ctx.beginPath(); ctx.moveTo(100,130); ctx.strokeStyle = '#009'; ctx.arcTo(200, 130, 200, 30, 100); ctx.stroke(); ctx.beginPath(); ctx.moveTo(200,30); ctx.strokeStyle = '#090'; ctx.arcTo(200, 190, 380, 190, 180); ctx.stroke(); } </script>
canvas {border:1px solid #ccc;}
<canvas id="quadro" width="400" height="200"> <p>Conteúdo alternativo para navegadores que não suportam canvas.</p> </canvas>