The Limaçon as a Conchoid of a Circle

Given is a unit circle and a fixed point on the circle. Let be a random point on the circle, and let be the line through and . The slider allows us to choose and fix a distance . The light blue points and are points from the line, on a distance to . As moves along the circle, the points and will draw the conchoid of the circle - a Limaçon.
  • Drag the slider to see how the shape of the Limaçon depends on the distance .