# Relationship between lines of symmetry and rotational

### Unit 15 Section 3 : Symmetry

9SS Demonstrate an understanding of line and rotation symmetry. . The relationship between the angle of rotation and the order of rotation is. Rotational symmetry occurs when rotating a body at a certain angle the What can you say about relationship between lines of symmetry and. A shape has a line of symmetry when the folded part sits perfectly on top with The order of rotational symmetry of a regular polygon is equal to the number of.

Line Symmetry Basically, a line of symmetry is a line that divides a figure into two mirror images. The figure is mapped onto itself by a reflection in this line.

A set of points has line symmetry if and only if there is a line, l, such that the reflection through l of each point in the set is also a point in the set.

### Line symmetry, reflective symmetry and rotational symmetry explained for parents | TheSchoolRun

May also be referred to as reflectional symmetry. Certain figures can be mapped onto themselves by a reflection in their lines of symmetry.

Some figures have one or more lines of symmetry, while other figures have no lines of symmetry. Remember, if you fold the figure on a line of symmetry, the folded sides coincide.

Not all lines that divide a figure into two congruent halves are lines of symmetry. The diagonal of a rectangle divides the rectangle into two triangles that are congruent same size and shape. But the diagonal line is NOT a line of symmetry. Folding along the diagonal does not coincide with the other side.

### Symmetry - Reflection and Rotation

The diagonal of a parallelogram also divides the figure into two triangles that are congruent. What is reflective rymmetry? The reflected shape will be exactly the same as the original, the same distance from the mirror line and the same size. What is rotational symmetry?

## What are line symmetry, reflective symmetry and rotational symmetry?

Rotational symmetry is when a shape or pattern can be rotated or turned around a central point and remains the same. It may be stated that a shape has a rotational symmetry of order X; this means that the shape can be turned around a central point and remain the same X times.

When are children taught about different kinds of symmetry in primary school?

In Year 2 children will be introduced to the concept of symmetry and taught to identify line symmetry in a vertical line. They may be given the shapes and asked to fold them or draw on a line of symmetry.

## Unit 15 Section 3 : Symmetry

In Year 3 children are taught to sort shapes into symmetrical and non-symmetrical polygons. In Year 4 children identify lines of symmetry in 2D shapes. They will become aware that shapes may have more than one line of symmetry and complete investigations about how many lines of symmetry shapes have.

Children will also learn to draw symmetrical patterns with respect to a specific line of symmetry. They will often use squared paper to do this task.

In Year 5 children are taught to reflect shapes and patterns in lines that are parallel to the axis.