Ellipse

<svg width="150" height="150" xmlns="http://www.w3.org/2000/svg">
  <rect width="100%" height="100%" fill="white" stroke="black" stroke-width="1" />
  <ellipse rx="75" ry="40" cx="75" cy="75" fill="green" />
</svg>

• rx is the horizontal radius (so half of the width of the ellipe).
• ry is the vertical radious (so half of the hight of the ellipse).
• cx is the horizontal center of the ellipse.
• cy is the vertical center of the ellipse.