Lesson Plan

Define a line of symmetry as a line across a two-dimensional figure such that the figure can be folded along the line into two matching parts

Identify whether a given two-dimensional figure has line symmetry

Draw all lines of symmetry for common two-dimensional figures (rectangles, squares, regular polygons, circles, letters, and real-world shapes)

Recognize that some figures have no lines of symmetry, some have exactly one, and some have multiple lines of symmetry

Distinguish a line of symmetry from a line that merely divides a figure into two equal-area parts but does not produce matching (mirror-image) halves

4.G.A.3

4.G.A.3: Recognize a line of symmetry for a two-dimensional figure as a line across the figure such that the figure can be folded along the line into matching parts. Identify line-symmetric figures and draw lines of symmetry.