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Lines of symmetry

A shape can be folded to see if it has a line of symmetry.

A shape has a line of symmetry when the folded part sits perfectly on top with all edges matching.

Line symmetry in regular polygons

A square is a regular polygon. It has four lines of symmetry and four sides.

A regular pentagon has 5 sides and 5 lines of symmetry.

The number of lines of symmetry in a regular polygon is equal to the number of sides.

Rotational symmetry

A shape has rotational symmetry when it can be rotated and it still looks the same.

The order of rotational symmetry of a shape is the number of times it can be rotated around a full circle and still look the same.

If the triangle is rotated a full 360°, it never looks the same except when it arrives back at its original starting position. It only has one order of rotational symmetry, the starting position.

The minimum order of rotational symmetry a shape can have is 1.

Rotational symmetry in regular polygons

The order of rotational symmetry of a regular polygon is equal to the number of sides.

Symmetry of quadrilaterals

There are six special quadrilaterals with different symmetrical properties.

Square

• A square has four lines of symmetry.
• It has rotational symmetry of order four.

Rectangle

• A rectangle has two lines of symmetry.
• It has rotational symmetry of order two.

Parallelogram

• A parallelogram has no lines of symmetry.
• It has rotational symmetry of order two.

Rhombus

• A rhombus has two lines of symmetry.
• It has rotational symmetry of order two.

Trapezium

• Some trapeziums have one line of symmetry. They are called isosceles trapeziums as they have 2 sides of an equal length like isosceles triangles.
• A trapezium has rotational symmetry of order one.

Kite

• A kite has one line of symmetry.
• It has rotational symmetry of order one.