.. _circle:

circle
======

.. index:: circles

.. image:: circle.png
   :align: right
   :width: 300px

..

  A *circle* is a plane figure contained by one line such that all the segments
  falling upon it from one point among those lying within the figure are equal
  to one another;

  -- Euclid

.. _center:

..

  And the point is called the *center* of the circle.

  -- Euclid


All :ref:`points <point>` on the perimeter of a circle are an equal distance from the center.

.. toctree::

   diameter/index.rst
   arc/index.rst
   semicircle/index.rst