Two-dimensional or three-dimensional figure with at least one axis of symmetry, a plane of symmetry or a centre of symmetry.
Various symmetric figures are shown below :
- An isosceles triangle has 1 axis of symmetry;
- A square has 4 axes of symmetry;
- A rectangle has 2 axes of symmetry;
- A rhombus has 2 axes of symmetry.
A solid may be symmetric if it has at least one plane of symmetry, which divides the solid into two identical solids. A cube has several planes of symmetry.
Figure APP’ below is symmetric with respect to the axis s.