options: Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures.

Classify two-dimensional figures based on the presence or absence of parallel or perpendicular lines, or the presence or absence of angles of a specified size. Recognize right triangles as a category, and identify right triangles.

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.
problem_activity: Stage 1: Lines of Symmetry
Required Preparation
Materials to Gather
Colored pencils, crayons, or markers
Materials to Copy
Blackline Masters
Centimeter Grid Paper - Standard
Centimeter Dot Paper - Standard

Narrative
Each student chooses whether to use dot or grid paper. Each student creates a half of a design and draws a line of symmetry. Students switch paper and complete each other’s designs.


correct_option_index: 2