Every edge on each of these three objects is a straight line.
The three objects on the board are:
Do all the edges on one object look the same length, or are some longer than others?
Show the three real-object photos as pupils settle. Take three hands-up answers, not open call-outs. Hold out for the word equal — nudge pupils toward comparing the sides, not just counting them.
A polygon is a closed flat shape made only of straight sides. Look at the two hexagons on the board. Look at the sides of each one. If every side matches and every corner matches, the shape is regular. If some sides are different lengths, it is irregular.
Regular means all the sides are equal and all the corners are equal. The last shape is a hexagon that looks a bit odd. Be ready to say what makes it different from the honeycomb hexagon.
Point to each shape in its group as the class watches, running a finger along the sides as you go. On the regular hexagon, count the equal sides aloud; on the irregular one, point out the two sides that are clearly a different length, then point to one wide corner and one narrow corner so the class sees the corners are uneven too. The irregular hexagon has the same number of sides as the honeycomb one — it is the side lengths that decide, not the count. Ask what is the same about these two, and what is different? before naming the rule.
Regular means all sides equal and all corners equal. Irregular means at least one side is different.
A pentagon has 5 sides, a hexagon has 6 and an octagon has 8. Regular means those sides are all equal.
Today we sort these polygons together: a pentagon, another pentagon, a hexagon, another hexagon, an octagon, and an octagon that has one short side.
For each shape, we check every side before we decide.
Talk this one through together — pupils take turns at the board and the class agrees or corrects out loud.
Send a different pupil up for each shape. Make them run a finger along all the sides before they drop the card. Watch for the trap: a shape can look regular at a glance but have one short side, so hold out for did you check every side, not just two? Revoice a strong answer: so the pentagon has five sides either way — it is whether they all match that makes it regular.
In your maths copy, draw a regular hexagon and an irregular hexagon side by side. Under them, write one sentence saying how you can tell them apart.
Walk the room glancing at whether both hexagons have six sides and whether the regular one's sides look even — no individual marking, this is whole-class copybook practice, not assessment.
We'll work through four sorts, each a bit harder:
This is the practice round — 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 rotated-shape round is the one that catches people out — a turned regular pentagon is still regular, so remind the class to count the sides, not judge by the way it is pointing. Give this round a little extra breathing room. The slightly-short-side round is the real stretch: a shape that looks regular is irregular if even one side is off, and its corner beside that short side will look different too. Press Check after each so the class sees the ✓ before moving on.
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