Unit 2 — Shapes, Structures, and Strength
Description
Students investigate how shape and structure relate to strength and stability. Through activities with crystals, eggs, and newspaper, students discover that curved shapes and triangles are stronger than other forms. Students apply biomimetic thinking to design protective structures for seeds and create shelters that use strong shapes. The unit culminates in building and testing rain gutters that must direct water effectively while remaining structurally sound.
Essential Questions
- What shapes are strongest and why?
- How does nature use shape to protect delicate things?
- How do engineers use shapes to solve design challenges?
Learning Objectives
- Identify strong shapes in nature and human-made structures
- Test materials to determine strength properties
- Design structures that protect contents while meeting constraints
- Build and test rain gutter prototypes using various materials
- Evaluate designs and suggest improvements based on test results
Supplemental Resources
- Tape for assembling rain gutter prototypes
- Index cards for recording test data on material strength
- Markers for labeling different shape designs
- Plastic page protectors used as dry-erase surfaces for recording observations
Engineering Design
Nature of Technology
Engineering, Technology, and Applications of Science
Geometry
Formative Assessments
- Observation of shape exploration and testing
- Seed protection design sketch with written reasoning
- Rain gutter construction and leak testing
- Group discussion of which shapes held up best
Summative Assessment
Functional rain gutter design that collects and directs water without leaking
Benchmark Assessment
— not configured —
Alternative Assessment
Students may demonstrate understanding through hands-on manipulation of shapes and materials with teacher observation and questioning, rather than written or sketch-based responses. Visual supports such as labeled pictures of strong shapes, real objects to sort, and sentence stems like 'This shape is strong because...' may be provided to support communication of ideas.
IEP (Individualized Education Program)
During hands-on testing and building activities, provide physical and verbal prompts to help students connect what they observe (e.g., a shape bending or holding) to the concept being explored. Allow students to demonstrate understanding through pointing, gesturing, or dictating their reasoning about strong shapes rather than producing written responses. Visual supports such as picture cards showing strong versus weak shapes can help scaffold design thinking and discussion participation. Break multi-step building tasks into clearly sequenced steps with visual cues so students can work more independently.
Section 504
Ensure students have access to a low-distraction workspace during building and testing tasks, as hands-on materials can create sensory and visual overload. Provide extended time for construction and observation phases, and offer preferential seating during group discussions about shape strength so students can fully access the conversation.
ELL / MLL
Use real objects, demonstrations, and visual comparisons (e.g., holding up a flat sheet versus a curved form) to make the concept of structural strength concrete before introducing related vocabulary. Preview key terms such as 'curve,' 'triangle,' 'stable,' and 'structure' with picture support, and allow students to use their home language when explaining their design thinking to a partner or teacher. Simple, repeated sentence frames during discussions can help students share observations about what shapes worked and why.
At Risk (RTI)
Connect the unit's core idea — that some shapes hold more weight or stay standing better — to familiar objects students encounter every day, such as the shape of a roof or an eggshell, to build confidence and activate prior knowledge. Offer entry points by letting students begin testing with simpler materials before progressing to more complex construction tasks, and pair them with a supportive partner during design challenges. Providing a partially constructed model to reference can reduce frustration and keep students engaged in the engineering process.
Gifted & Talented
Invite students to investigate why certain shapes are stronger at a deeper level by exploring structural patterns found in nature and architecture beyond what is introduced in the unit. Challenge them to consider additional constraints for their designs — such as limiting the number of materials used or adding a weight requirement — and to document their reasoning about trade-offs in an engineering journal using drawings and dictated notes. Students can also be encouraged to propose and test a redesign of their rain gutter based on what they observe during testing, practicing iterative engineering thinking.