New
New
Make shapes by joining two polygons in different ways
I can make compound shapes by joining two polygons in different ways.
Lesson 1 of 10
New
New
- Year 3
Make shapes by joining two polygons in different ways
I can make compound shapes by joining two polygons in different ways.
Lesson details
Key learning points
- The same parts can create a different whole.
- Lines are parallel because they are always the same distance apart.
- A quadrilateral with two pairs of parallel sides is called a parallelogram.
Keywords
Polygon - A 2D shape made up of three or more straight lines.
Quadrilateral - Polygons with four straight sides and four vertices.
Common misconception
Pupils do not recognise the new shape and only identify the smaller shapes it is composed of.
Using plastic shapes to compose a new shape and drawing around the shape can support pupils to see the properties of the new shape. Drawing around removes the joined sides inside the new polygon.
Allow time for pupils to explore making polygons with two identical triangles. You could use identical plastic shapes to support manipulation.
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.A __________ is a 2D shape made up of three or more straight lines.
A __________ is a 2D shape made up of three or more straight lines.
quadrilateral
Q2.Which of these statements are true for all quadrilaterals?
Which of these statements are true for all quadrilaterals?
They have a line of symmetry.
They have two sides the same length.
Q3.Which of these shapes are quadrilaterals?
Which of these shapes are quadrilaterals?
b
c
Q4.Which of these describe the properties of all triangles?
Which of these describe the properties of all triangles?
1 right angle
2 sides the same length
Q5.Which of these shapes are triangles?
Which of these shapes are triangles?
b
c
Q6.Match the description to the type of shape.
Match the description to the type of shape.
Assessment exit quiz
6 Questions
Q1.Two triangles have been joined to make new polygons.
Which new shape is not a quadrilateral?
Two triangles have been joined to make new polygons.
Which new shape is not a quadrilateral?
a
c
d
Q2.Complete the sentence.
Lines are parallel when __________
Complete the sentence.
Lines are parallel when __________
they get closer together.
they get further apart.
Q3.A rectangle is a quadrilateral. What are the properties of a rectangle?
A rectangle is a quadrilateral. What are the properties of a rectangle?
Four equal sides.
Only one pair of parallel sides.
Q4.Look carefully at this polygon. Which statements are true?
Look carefully at this polygon. Which statements are true?
It has four right angles.
It has five sides.
Q5.True or false. These shapes are all rectangles.
True or false. These shapes are all rectangles.
True
Q6.Which of these quadrilaterals does not have any parallel sides?
Which of these quadrilaterals does not have any parallel sides?
a
c
d
