New
New
Year 1

Explore, discuss and identify shapes that are and are not triangles

I can say if a shape is a triangle or not and explain why.

New
New
Year 1

Explore, discuss and identify shapes that are and are not triangles

I can say if a shape is a triangle or not and explain why.

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Lesson details

Key learning points

  1. Use everyday language to describe what different shapes look like.
  2. Identify shapes that are triangles because they have 3 straight sides and 3 vertices.
  3. A vertex is the corner of the shape where the sides meet.

Common misconception

Children may mistake some 'triangle-like' shapes as triangles.

Provide cut-outs of shapes to handle and explore. Make a list of properties a triangle must have and discuss them for each cut-out.

Keywords

  • Sides - The edges of a shape.

  • Vertices - The corners of a shape where two or more sides meet.

  • Triangle - A 2D shape with three straight sides and three vertices.

  • Straight - A line or surface with no curves.

Ensure children have plenty of opportunities to handle cut-outs of triangles and triangle-like shapes as well as looking at pictures so they can handle them and describe how the sides and vertices feel in their hands.
Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

Video

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6 Questions

Q1.
Which shape is Alex describing?
An image in a quiz
A
Correct answer: B
C
Q2.
Which shape has 1 straight side and 1 curved line?
Correct answer: A
B
C
Q3.
How many vertices does this shape have?
An image in a quiz
2
3
Correct answer: 4
5
Q4.
Which line has been sorted correctly?
An image in a quiz
A
Correct answer: B
C
Q5.
Tick all the names that are 2D shapes.
Correct answer: circle
cube
Correct answer: triangle
Correct answer: rectangle
cone
Q6.
Look how these shapes have been sorted. Which shape has been placed in the wrong set?
An image in a quiz
A
B
Correct answer: C

6 Questions

Q1.
Which shape has only 3 straight sides?
A
Correct answer: B
C
Q2.
Which shape has only 3 vertices?
Correct answer: A
B
C
Q3.
Find the shape that has only 3 vertices.
A
Correct answer: B
C
Q4.
Tick all the triangles.
A
Correct answer: B
C
Correct answer: D
Q5.
This shape is not a triangle because __________.
An image in a quiz
Correct answer: it has more than 3 sides.
it has curved lines.
it has no vertices.
Q6.
Which shape doesn't belong in this set?
An image in a quiz
Correct answer: A
B
C

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