SYMMETRY

Symmetry is when one half of a shape is the same as the other half.
It is like a perfect mirror image! 🪞⭐
WHAT IS SYMMETRY?
  • When a shape or object can be divided into two equal parts that are mirror images of each other, it is symmetrical.
  • The dividing segment or fold line is called the line of symmetry.
  • Not all shapes have symmetry—some are completely asymmetrical!
Look around you! Symmetry is found everywhere in nature and art!
LINES OF SYMMETRY

The dotted line shows the perfect line of symmetry:

Leaf
(1 Line)
Letter A
(1 Line)
Rectangle
(2 Lines)
Square
(4 Lines)
Folding a shape along its symmetry line makes both edges map onto each other perfectly!
QUICK FACTS
  • A symmetrical shape must contain at least one clean line of symmetry.
  • Shapes can contain multiple distinct axes lines (e.g. circles contain infinite axes).
  • The line of symmetry always bisects a target shape into matching identical halves.
  • Verification tests include structural folding mappings or clear mirror line checks.
If a mirror reflection perfectly completes the original object, it is symmetrical!
GAME: IS IT SYMMETRICAL?

Identify if the shape is Symmetrical or Asymmetrical:

HOW TO CHECK SYMMETRY?
✏️
1. Draw a Test Line Draw a line down the middle of the shape. If both sides are exactly identical mirror components, it possesses symmetry.
🪞
2. Use a Mirror Place a straight hand mirror directly along your proposed centerline split. If the mirror reflection cleanly matches the hidden side, your line is correct.
FUN ACTIVITY: COUNTING LINES

Enter the exact number of lines of symmetry for each shape:

Circle
Rectangle
Equilateral Triangle
Regular Hexagon
SYMMETRY IN COMMON SHAPES
Shape
Name
Lines of Symmetry
Circle
Infinite (Countless)
Square
4 Lines
Rectangle
2 Lines
Equilateral Triangle
3 Lines
💡 A regular polygon has the same number of lines of symmetry as its number of sides!
SYMMETRY IN REAL LIFE
Taj Mahal Architecture
Nature's Flowers
Sports Footballs
Clothing Clothes
THINK AND ANSWER
KEY POINTS TO REMEMBER
  • Symmetry means identical halves that match up perfectly when folded.
  • The dividing bisector line is called the line of symmetry.
  • A shape can contain 0, 1, 2, or many lines of symmetry.
  • We check for symmetry easily by folding or using standard mirror lines.
  • Symmetry creates balance, composition, and beauty in design and nature!
FOLD LINE