M19 - Symmetry
Symmetry 1. Key vocabulary Line of symmetry: A line that divides a shape into two matching mirror-image halves. Rotational symmetry: A shape matches its original position after a rotation of less than one complete turn. Order of rotational symmetry: The number of times a shape matches itself during one complete turn of $360^\circ$. Axis of rotational symmetry: A line about which a shape or solid can be rotated and remain unchanged. Plane of symmetry: A flat plane that divides a solid into matching mirror-image halves. A shape can have line symmetry, rotational symmetry, both, or neither. ...