Unit 8: Properties of Two-dimensional Shapes

Students classify triangles and quadrilaterals based on the properties of their side lengths and angles, and learn about lines of symmetry. They use their understanding of these attributes to solve problems, including problems involving perimeter and area.

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What this unit covers

A Side Lengths, Angles, and Lines of Symmetry · 6 lessons

Goals

• Classify triangles (including right triangles), parallelograms, rectangles, rhombuses, and squares based on the properties of their side lengths and angles.
• Identify and draw lines of symmetry in two-dimensional figures.

Lessons

1. Ways to Look at Figures
2. Ways to Look at Triangles
3. Ways to Look at Quadrilaterals
4. Symmetry in Figures (Part 1)
5. Symmetry in Figures (Part 2)
6. All Kinds of Attributes (Optional)

B Reason about Attributes to Solve Problems · 5 lessons

Goals

• Solve problems involving unknown side lengths, perimeter, area, and angle measurements using the known attributes and properties of two-dimensional shapes.

Lessons

1. Ways to Find Unknown Length (Part 1)
2. Ways to Find Unknown Length (Part 2)
3. Symmetry in Action (Optional)
4. Ways to Find Angle Measurements (Optional)
5. Symmetry in Sports (Optional)

Helpful to know first

The curriculum says this unit builds on these.

Grade 4 Math · Unit 7 Angles and Angle Measurement

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Grade 3 Math · Unit 7 Two-Dimensional Shapes and Perimeter

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Grade 4 Math · Unit 3 Extending Operations to Fractions

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