Grade 3 · Unit 8: Location and transformation

Symmetry

Fold it – do the halves match?

Symmetry in nature

A butterfly’s wings match on both sides. It is symmetrical. Leaves, flowers and faces are nearly symmetrical too.

Lines of symmetry

A line of symmetry splits a shape into matching halves. Some shapes have many lines. A circle has an endless number!

Completing a reflection

Each point is the same distance from the mirror line on both sides. Count squares to the line, then count the same on the other side. The reflection faces the opposite way.

Symmetry in regular shapes

A square has 4 lines of symmetry. A regular hexagon has 6. A rectangle that is not a square has only 2.

Diagonal lines and tiles

A square has 4 lines of symmetry: 2 straight and 2 diagonal. Some shapes look the same when turned – rotational symmetry. Floor tiles and jali screens use symmetry and tessellation.

What I learnt

• I can find lines of symmetry.
• I can complete a symmetrical shape.