Definition:Rotational Symmetry/Axis

Definition

Let $F$ be a geometric figure.

Let $\map R F$ be a rotational symmetry around the axis of rotation $AB$.

Then $AB$ is referred to as an axis of rotational symmetry of $F$.

Order

Let $F$ be a geometric figure.

Let $\map R F$ be a rotational symmetry around the axis of symmetry $AB$.

Let the order of $R$ be $n$.

Then $AB$ is likewise defined as being an axis of order $n$.

Also known as

An axis of rotational symmetry is also known as just an axis of symmetry, if it is clear that the symmetry under discussion is indeed rotational.

Also see

• Definition:Rotational Symmetry
• Definition:Axis of Symmetry
• Definition:Axis of Bilateral Symmetry

• Results about axes of rotational symmetry can be found here.

Sources

• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): symmetry
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): symmetry