Geometry Basics: Shapes and Symmetry

Geometric Shapes

• Geometric shapes are shapes without any math attached to them, e.g. a circle drawn on a billboard.
• Examples of geometric shapes include triangles, squares, octagons, and curvy shapes.
• Even the shape of a dog's shadow is a geometric shape.

Lines of Symmetry

• A line of symmetry is a line in a shape that splits it in half, with each half being a mirror image of the other.
• The line of symmetry in a circle goes through the center of the circle, dividing it into two identical halves.
• Geometric shapes can have more than one line of symmetry.

Circle

• A circle has an infinite number of lines of symmetry, as it can be folded in many ways, as long as the fold goes through the center.

Rectangle

• A rectangle has two lines of symmetry: one sideway and one up or down.

Capital Letter A

• The capital letter A has one line of symmetry, which is when it is folded in half sideways.

Discovering Lines of Symmetry

• To find the lines of symmetry in a shape, try folding it in different ways to see if the halves match up perfectly.
• Start folding different shapes to discover more lines of symmetry.