Grade 4 · Geometry

CCSS.MATH.CONTENT.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.

Read this standard on the official Common Core site

Lessons that teach this standard

• Parallel Lines, Perpendicular Lines and Symmetry

  How to sort flat figures by parallel sides, perpendicular sides and angle size, why a right triangle is its own category, and how to find every line of symmetry.