Polygons with Sides

Overview

This 20-minute lesson is designed to engage Year 3 students (ages 7-8) in recognising and drawing polygons by joining marked points, with a focus on identifying parallel and perpendicular sides. The plan follows the National Curriculum for England, particularly addressing objective 3G-2: Draw polygons by joining marked points, and identify parallel and perpendicular sides.

The lesson is highly interactive, utilising the "I do, We do, You do" teaching model and rich talk strategies to maximise participation and conceptual understanding in a small class of 27 students.

National Curriculum Links

Geometry: properties of shapes (Year 3)
- Draw 2-D shapes and make 3-D shapes using modelling materials; recognise angles as a property of shape or a description of a turn.
- Identify right angles, recognise that two right angles make a half-turn, three make three quarters of a turn and four a complete turn; identify whether angles are greater than or less than a right angle.
- Identify parallel and perpendicular lines.
Programme of Study Reference: Geometry (3G-2)

Learning Objectives

By the end of the lesson, pupils will be able to:

Draw polygons by joining marked points accurately.
Identify and use correct mathematical vocabulary: polygon, parallel sides, perpendicular sides.
Recognise parallel and perpendicular sides in polygons through visual and practical activities.
Verbally explain how to identify parallel and perpendicular sides in a polygon.

Resources

Polygons printed on A3 sheets with marked points (triangles, quadrilaterals, pentagons).
Large whiteboard and marker pens.
Small sets of coloured string or plastic sticks (for constructing polygons physically).
Rulers and set squares.
Individual mini-whiteboards for students.
Parallel and perpendicular side flashcards.
Visual prompts showing parallel and perpendicular lines.

Lesson Structure (20 Minutes)

1. Starter / Engagement (3 mins)

Talk Strategy: Think-Pair-Share

Question to class: "Can anyone tell me what a polygon is?"
Allow a student or two to answer, then clarify: a polygon is a flat shape with straight sides.
Show quick examples of familiar polygons (triangle, square, pentagon).
Introduce the vocabulary: "parallel" means lines that never meet and go in the same direction; "perpendicular" means lines that meet to form a right angle (90°).
Use parallel and perpendicular flashcards to visually reinforce.

2. I Do (Modelled Teaching - 5 mins)

Display a polygon joined by marked points on the whiteboard. Use a ruler and set square to draw and highlight sides.
Verbally identify examples of parallel and perpendicular sides, underlining why: “See these two sides are parallel because they have equal distance apart and will never meet.” “These sides meet at a right angle so they are perpendicular.”
Annotate the polygon, labelling parallel and perpendicular sides.
Talk aloud your thinking process, modelling mathematical language and reasoning clearly.

3. We Do (Guided Practice - 7 mins)

Hand out printed polygons with marked points to pairs.
Guide students through drawing polygons by joining points using rulers and set squares.
In pairs, pupils find and discuss which sides are parallel or perpendicular, using vocabulary.
Circulate, listening to conversations; prompt with questions like:
“How do you know those sides are parallel?”
“What angle do these sides make?”
Call out a pair to explain their polygon identification to the class (using mini-whiteboard to illustrate).
Encourage others to ask questions or add observations (modelling sentence starters e.g., “I agree because...”, “I have a question about...”).

4. You Do (Independent Practice - 4 mins)

Each pupil receives a mini-whiteboard with a different set of marked points.
Individually, they draw their polygon and label as many parallel and perpendicular sides as they can identify.
Encourage them to write a sentence: “These sides are parallel because…” Or “These sides are perpendicular because…”
Collect mini-whiteboards at the end for quick formative assessment.

5. Plenary / Assessment (1 min)

Recap core vocabulary: polygon, parallel, perpendicular.
Rapid-fire questions: Point to the parallel sides on the whiteboard polygon; "What kind of angle do these sides make?"
Praise verbal explanations and correct use of vocabulary.
Highlight how polygons are all around us and recognising parallel and perpendicular sides helps us understand shapes better.

Assessment and Feedback

Formative assessment through questioning during “We do” and observation of “You do” activity.
Use mini-whiteboards to quickly identify misconceptions about parallel and perpendicular sides or drawing accuracy.
Immediate verbal feedback to support conceptual clarity and correct terminology use.

Stretch / Next Steps (if time allows)

Challenge: Can you draw a polygon with no parallel or perpendicular sides? What shape might this be?
Explore angles formed by non-perpendicular intersecting sides briefly to extend understanding.

Talking Points to Impress Interview Panel

Use of "Think-Pair-Share" and "Talk Partners" builds mathematical language skills and confidence.
Clear demonstration of I do, We do, You do scaffolding ensures stepwise learning and independence.
Interactivity and multi-sensory resources (strings, plastic sticks, set squares) enable kinaesthetic and visual learning styles.
Instant formative assessment with mini-whiteboards allows live teacher responsiveness.
Links classroom learning explicitly to everyday context and vocabulary – key for Year 3 engagement.

This lesson plan meets and embodies the National Curriculum geometrical objectives for Year 3, ensuring pupils develop both procedural and conceptual fluency in polygons, parallel, and perpendicular lines within a rich talk-based classroom environment.

Teaching Instructions