Centre (mathematics)

In mathematics, centre may refer to:


 * In an algebraic structure, elements that commute with every element of the structure
 * The centre of a group, elements that commute with every group element
 * The centre of a circle
 * The centre of mass, centroid or barycentre of a geometrical figure
 * In triangle geometry
 * The centroid, intersection of the medians
 * The circumcentre, intersection of the perpendicular bisectors of the sides, centre of the circle through the vertices
 * The nine-point centre
 * The orthocentre, intersection of the altitudes
 * The incentre, centre of a circle tangent to the sides
 * The excentres, centres of the three circles internally tangent to one side and externally to the other two