EDEXCEL GCSE FOUNDATION MATHS - What is Line Symmetry

Edexcel GCSE Foundation Maths: What is Line Symmetry?

What is Line Symmetry?

Line symmetry, also known as reflection symmetry, occurs when a shape can be folded along a line so that the two halves match perfectly. The line of symmetry divides the shape into two identical mirror images.

Key Terms:

• Line of Symmetry: The imaginary line that divides the shape into two identical halves.
• Mirror Image: The reflected half of the shape that is identical to the original half.

Identifying Line Symmetry:

1. Fold Test: Imagine folding the shape along a line. If the two halves match perfectly, the line is a line of symmetry.
2. Equal Distance: Points on the shape should be the same distance away from the line of symmetry on either side.

Examples:

• Square: A square has four lines of symmetry. You can fold it in half horizontally, vertically, and diagonally.
• Circle: A circle has infinite lines of symmetry. You can fold it along any diameter.
• Rectangle: A rectangle has two lines of symmetry, horizontally and vertically.

Drawing Lines of Symmetry:

1. Identify the fold line: Look for where the shape can be folded in half.
2. Draw a dotted line: Use a ruler to draw a dotted line along the fold line. This represents the line of symmetry.

Practice Exercise:

Instructions:

1. Identify the lines of symmetry in the following shapes.
2. Draw the lines of symmetry on the shapes.

[Image of a square, rectangle, and circle]

Answer Key:

[Image of the shapes with lines of symmetry drawn on them]

Key Points:

• Not all shapes have lines of symmetry.
• A shape can have more than one line of symmetry.
• Line symmetry is a key concept in geometry and design.

Further Exploration:

• Explore different shapes and their lines of symmetry.
• Investigate the relationship between line symmetry and other geometric concepts like angles and sides.
• Design your own shapes with specific lines of symmetry.