Home›Lesson Plans›Mathematics›Geometry · Grade 3

2-D Shapes: Sorting by Sides, Angles & Corners

Students explore flat shapes and learn to classify them by their attributes — the number of sides, the angles, and which sides run parallel.

Grade 3Geometry45 minutes1 class periodGradual ReleaseExplicit teaching4 StandardsCommon Core
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Lesson at a Glance

Everything you need before the bell rings

Learning Objectives

Students will be able to…

  • ✓Identify 2-D shapes by their number of sides and angles.
  • ✓Describe shape attributes (parallel sides, right angles).
  • ✓Classify quadrilaterals (square, rectangle, rhombus, trapezoid).
  • ✓Explain why a square is a special rectangle.
Essential Question

A square and a rhombus both have four equal sides — so what makes them different? Shapes are sorted by their attributes, not just their looks.

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Lesson Phases
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Vocabulary Terms
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Standards Aligned
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Interactive Task
Model · Interactive Tool

The Shape Explorer

Project this and tap each shape. Have students record the number of sides and angles and one special attribute for each.

🔺 Explore 2-D shapes — tap each oneTry it

The Lesson · Gradual Release (I Do · We Do · You Do)

45 minutes, five moves

Tap any phase to open the teacher moves and student actions.

1

Launch — Same but Different

5 min

A square and a rhombus — what’s the difference?

👩‍🏫 Teacher Moves

  • Show a square and a rhombus.
  • Ask what makes them different.
  • Set the goal: sort by attributes.

🎒 Student Actions

  • Compare the two shapes.
  • Guess the key difference.
  • Predict what “attribute” means.
2

I Do — Name the Attributes

10 min

Teacher describes a shape.

👩‍🏫 Teacher Moves

  • Count sides, angles, and vertices of a square.
  • Point out right angles and parallel sides.
  • Define “quadrilateral.”

🎒 Student Actions

  • Copy the shape.
  • Label sides, angles, vertices.
  • Say the attributes aloud.
3

We Do — Explore Together

12 min

Class drives the Shape Explorer.

👩‍🏫 Teacher Moves

  • Tap through all six shapes.
  • Compare their attributes.
  • Sort the quadrilaterals.

🎒 Student Actions

  • Tap each shape.
  • Record sides, angles, parallels.
  • Group the four-sided shapes.
4

You Do — On Your Own

13 min

Students classify shapes.

👩‍🏫 Teacher Moves

  • Assign a shape sort by attribute.
  • Include “Why is a square a rectangle?”
  • Check attribute language.

🎒 Student Actions

  • Sort shapes by their attributes.
  • Explain the square–rectangle link.
  • Draw and label a quadrilateral.
5

Close — Sort It Out

5 min

Classify one shape together.

👩‍🏫 Teacher Moves

  • Show a mystery shape.
  • Have students name its attributes.
  • Hand out the exit ticket.

🎒 Student Actions

  • Describe the shape’s attributes.
  • Name what kind it is.
  • Complete the exit ticket.
Standards Alignment

Built to the standards you report on

Aligned to the Common Core State Standards for Mathematics, including the Standards for Mathematical Practice.

CCSS
3.G.A.1

Understand that shapes in different categories may share attributes; recognize rhombuses, rectangles, and squares as examples of quadrilaterals.

CCSS
4.G.A.2

Classify two-dimensional figures based on parallel or perpendicular lines and angle size.

CCSS
4.G.A.1

Draw and identify points, lines, rays, angles, and parallel and perpendicular lines.

SMP
MP.7

Look for and make use of structure when classifying shapes.

Differentiation

One lesson, every learner

Multilingual Learners

ELL / EMERGING READERS
  • Sort real shape cutouts by number of sides.
  • Sentence frame: “This shape has ___ sides and ___ angles.”
  • Label attributes with picture words.

Support & Access

IEP / 504
  • Focus on counting sides and corners first.
  • Provide a shape-attribute chart to fill in.
  • Use physical shape tiles to sort.

Stretch & Extend

GIFTED / EARLY FINISHERS
  • Explore right, acute, and obtuse angles.
  • Build a shape hierarchy (square → rectangle → quadrilateral).
  • Find shapes with parallel and perpendicular sides.
Materials

What to gather

  • 📽️Projector / board
  • 📓Math notebooks
  • 💻The Shape Explorer
  • 📐Shape tiles / cutouts
  • 📏Rulers
  • 🎫Exit-ticket slips
Vocabulary

Key terms — hover for a quick definition

polygona closed shape with straight sidessidea straight edge of a shapevertexa corner where sides meetanglethe space where two sides meetright anglea square 90° cornerparallellines that never meetquadrilaterala 4-sided shapeattributea feature used to describe a shape
Evaluate

Exit Ticket

Preview the three formative checks. Tap “Sample answer” to see what mastery looks like — hide them before you print for students.

QUESTION 1
How many sides and angles does a hexagon have?
6 sides and 6 angles.
QUESTION 2
Name one way a square and a rectangle are the same and one way they are different.
Same: both have 4 right angles and opposite sides parallel. Different: a square has all four sides equal, while a rectangle only needs opposite sides equal.
QUESTION 3
What makes a shape a quadrilateral?
It is a closed shape with exactly four straight sides (and four angles).

Going deeper? Build a shape hierarchy.

Have students arrange quadrilaterals in a family tree — showing how a square fits inside “rectangle,” “rhombus,” and “quadrilateral.” A printable hierarchy template is in the Math library.

Study · Flashcards

Study the key terms

Tap a card to flip it, then rate whether you knew it. Built from this lesson’s vocabulary.

🃏 2-D Shapes & Their AttributesFlip
Card 1
Term
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Meaning
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Practice · Quiz

Check your understanding

A quick self-check with instant feedback, drawn from this lesson’s key terms.

📝 2-D Shapes & Their AttributesQuiz
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Question 1
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Practice · Worksheet

Printable worksheet

A print-and-go review sheet with a built-in answer key. Tap “Show answer key” to reveal answers, or print the clean version for students.

🖨️ 2-D Shapes & Their AttributesPrint
Name: ________________________
Date: ____________

Part A · Write the word that matches each meaning

Word bank: angle, attribute, parallel, polygon, quadrilateral, right angle, side, vertex
  1. a square 90° corner
  2. lines that never meet
  3. a feature used to describe a shape
  4. the space where two sides meet
  5. a corner where sides meet
  6. a straight edge of a shape
  7. a closed shape with straight sides
  8. a 4-sided shape

Part B · Show what you learned

  1. How many sides and angles does a hexagon have?
  2. Name one way a square and a rectangle are the same and one way they are different.
  3. What makes a shape a quadrilateral?
Answer key — Part A: 1) right angle · 2) parallel · 3) attribute · 4) angle · 5) vertex · 6) side · 7) polygon · 8) quadrilateral
Part B: 1) 6 sides and 6 angles. 2) Same: both have 4 right angles and opposite sides parallel. Different: a square has all four sides equal, while a rectangle only needs opposite sides equal. 3) It is a closed shape with exactly four straight sides (and four angles).