Center

<p>In <a href="https://en.wikipedia.org/wiki/Geometry" title="Geometry">geometry</a>, a <b>centre</b> (or <b>center</b>) (from <a href="https://en.wikipedia.org/wiki/Ancient_Greek_language" class="mw-redirect" title="Ancient Greek language">Greek</a> <i>κέντρον</i>) of an object is a point in some sense in the middle of the object. According to the specific definition of centre taken into consideration, an object might have no centre. If geometry is regarded as the study of <a href="https://en.wikipedia.org/wiki/Isometry_group" title="Isometry group">isometry groups</a> then a centre is a fixed point of all the isometries which move the object onto itself.</p>