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Lesson 2 of 10
Describe and name polygons, including triangles and quadrilaterals
I can recognise and describe polygons including triangles and quadrilaterals.
Lesson 2 of 10
New
New
Describe and name polygons, including triangles and quadrilaterals
I can recognise and describe polygons including triangles and quadrilaterals.
Lesson details
Key learning points
- The names of polygons are linked to the number of sides/vertices they have.
- A quadrilateral is any polygon with 4 sides.
- A triangle is any polygon with 3 sides.
- Squares and rectangles are quadrilaterals.
Keywords
Quadrilateral - A polygon with 4 sides and 4 vertices.
Rectangle - A polygon with 4 sides and 4 'square corners'.
Square - A polygon with 4 equal sides and 4 'square corners'.
Triangle - A polygon with 3 sides.
Common misconception
Children may mistake a 'triangle-like' shape for a triangle.
Provide opportunities to explore and handle cut-outs of triangles and triangle-like shapes. Describe and compare how the sides and corners feel. Touch the part of the shape that shows that it is not a triangle and explain how you know.
When children are sorting shapes into sets, they would benefit from having cut-outs of shapes, as although not strictly 2D, they will be able to handle them when deciding which set to place each in.
Teacher tip
Licence
This content is © Oak National Academy Limited (2025), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Which of these shapes are polygons?
Which of these shapes are polygons?
b
c
Q2.Which of these shapes are not polygons?
Which of these shapes are not polygons?
b
d
Q3.Which of the statements are true for all polygons?
Which of the statements are true for all polygons?
They are 3D shapes.
Q4.What is the same about all of these polygons?
What is the same about all of these polygons?
They are all 3D shapes.
Q5.This polygon has sides and vertices.
This polygon has sides and vertices.
Q6.Which polygon should not be part of this set? Polygon .
Which polygon should not be part of this set? Polygon .
Assessment exit quiz
6 Questions
Q1.Match the name of the shape with its properties.
Match the name of the shape with its properties.
have 3 vertices and 3 straight sides
have 4 vertices and 4 straight sides
Q2.Which of these shapes is not a triangle?
Which of these shapes is not a triangle?
a
b
d
Q3.Which of these shapes are quadrilaterals?
Which of these shapes are quadrilaterals?
a
b
Q4.Which shape should not be part of this set?
Which shape should not be part of this set?
a
c
d
Q5.This shape is a quadrilateral and also a .
This shape is a quadrilateral and also a .
Q6.This shape is not a triangle because...
This shape is not a triangle because...
it is a quadrilateral.