2D Shapes: Sides, Vertices and Naming

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1 Getting Started
2 Watch and Notice
3 Try It Together
4 Draw and Label in Your Copy
5 Class Challenge
6 What Did We Notice?
7 What's Next
Pupil practice

1 - Getting Started ~4 mins

Look at these three everyday things: a triangular yield road sign, a square window pane and a slice of pizza.

What is the same about how we could describe each one? Hands up: how many straight sides does each one have, and what do we call the pointy corners where the sides meet?

Teacher Notes

Take three hands-up answers, not open call-outs. Display real photos of the three objects if you have them, otherwise sketch them on the board.

Steer the talk toward two ideas the lesson needs: straight sides and corners. Don't name the shapes yet, that comes in Watch and Notice.

👇 Mark your steps as done as you complete them.

+5 XP

2 - Watch and Notice ~8 mins

Triangle

Watch the first shape drop into its side-count group as we count together. Count the straight sides with me: one, two, three. Now count the corners. A triangle has three straight sides and three corners. The proper word for a corner is a vertex, and when there is more than one we say vertices. So a triangle has three vertices.

Square

Watch the next shape drop into its group. Count the sides: all four are the same length, and there are four vertices. Any flat shape with four straight sides is called a quadrilateral. A square is a special quadrilateral where all four sides are equal.

Pentagon

This shape has five straight sides and five vertices. We call a five-sided shape a pentagon.

Hexagon

And the last one has six straight sides and six vertices. A six-sided shape is a hexagon.

Teacher Notes

Each shape is a display drag-sort: when you advance the slide, the shape animates into its matching side-count group on its own. You do not drag it. Talk the class through the count aloud as it lands.

Triangle (3 sides, 3 vertices) — touch each side and corner as you count; introduce vertex / vertices here as the new word for corners.
Square (4 equal sides, 4 vertices) — point out all four sides are the same length, then name a four-sided shape a quadrilateral and note a square is a special one.
Pentagon (5 sides, 5 vertices) — link to penta meaning five if your class enjoys word-roots.
Hexagon (6 sides, 6 vertices) — the new vocabulary to lock in today is vertex / vertices and quadrilateral.

For each shape, the number of sides always equals the number of vertices — let the class notice this themselves.

👇 Mark your steps as done as you complete them.

+10 XP

3 - Try It Together ~11 mins

Today we'll sort shapes into groups by how many sides they have. The groups are 3 sides, 4 sides, 5 sides and 6 sides.

Tip

We'll look at a shape card, count its straight sides together, and drag it into the right group. Some cards are turned on their side to try and trick us, so count carefully.

Sort shapes by their sides

Teacher Notes

This round is for talking it through together — pupils take turns at the board and the class agrees or corrects out loud.

Show one shape card at a time. Ask a pupil to count the sides aloud before dragging. The class confirms the count, then the pupil drops it in the matching group.

Deliberately include a few rotated shapes so pupils learn that turning a shape does not change how many sides it has. Revoice strong reasoning: so even though the pentagon is upside down, it still has five sides.

+15 XP

4 - Draw and Label in Your Copy ~4 mins

COPYBOOK MOMENT

In your maths copy, draw a triangle and a pentagon. Beside each shape, write how many sides and how many vertices it has.

Teacher Notes

Walk the room glancing at the labels — check pupils write the side count and vertex count for each shape. For pupils who find drawing the pentagon tricky, hand out a pre-printed outline to label. No marking, this is whole-class copybook practice, not assessment.

+10 XP

5 - Class Challenge ~7 mins

Today we work through these sorting rounds together. We start with clear regular shapes, then sort a mix of regular and stretched shapes, then shapes shown turned so they look unfamiliar, and finally a set of four-sided shapes that all go in the same group.

Key point

Remember: count the sides, not the way it is turned. A square, a rhombus and a trapezium all have four sides, so they all go in the 4 sides group, even though we give them different names.

Sorting challenge

Teacher Notes

This round is the practice bank — pupils take turns at the board, check each answer, and the class confirms before moving on. Keep the board work brisk rather than over-explaining.

The challenge bank rises in difficulty. For the last round, say each shape's name aloud as it appears (rhombus, trapezium) and point out that all four shapes have four straight sides, so they share the 4 sides group even though their names differ — counting sides gets you to the group; the name needs a second look.

+15 XP

Pupil practice

Module 7 · 2D and 3D Shapes and Angles Data & Chance

Lesson 71 · 2D Shapes: Sides, Vertices and Naming

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Teacher Class Feed

1 - Getting Started ~4 mins

2 - Watch and Notice ~8 mins

Triangle

Square

Pentagon

Hexagon

3 - Try It Together ~11 mins

Sort shapes by their sides

4 - Draw and Label in Your Copy ~4 mins

5 - Class Challenge ~7 mins

Sorting challenge

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