Transcript Slides - Nuffield Foundation

Nuffield Free-Standing Mathematics Activity
Geometrical design
© Nuffield Foundation 2011
Geometrical design
Can you name any of the geometrical shapes in these pictures?
This activity is about recognising shapes and their properties
Left-hand photo Decoramic Tile Centre http://www.decoramic.co.uk/
Think about
What is special about….
parallel lines
are always the same
distance apart
perpendicular lines
meet at 90
Triangles
have 3 sides and 3 angles
sum of the angles = 180
Think about
a right-angled triangle
What is special about ….
an obtuse-angled triangle
an acute-angled triangle
has one angle
of 90
has one angle
greater than 90
Think about
Why is it not possible for a triangle to
have more than one right angle?
has three angles
all less than 90
Triangles
Think about
What is special about….
an equilateral triangle
an isosceles triangle
a scalene triangle
has
3 equal sides and
3 equal angles.
has
2 equal sides and
2 equal angles.
Think about
What is each angle in an equilateral triangle?
has
3 different sides and
3 different angles.
Polygons
Think about
the names of these polygons….
A quadrilateral has 4 sides.
Sum of the angles = 360
A pentagon has 5 sides.
A hexagon has 6 sides.
An octagon has 8 sides
Quadrilaterals
Think about …
What is special about these quadrilaterals?
Rectangle
Square
Opposite sides equal
Opposite sides parallel
All sides equal
Opposite sides parallel
All angles are 90⁰
All angles are 90⁰
Quadrilaterals
Think about …
What is special about these quadrilaterals?
Parallelogram
Opposite sides equal
Opposite sides parallel
Opposite angles equal
Rhombus
All sides equal
Opposite sides parallel
Opposite angles equal
Quadrilaterals
Think about
What is special about these quadrilaterals?
Trapezium
Kite
One pair of sides parallel
Two pairs of equal sides
One pair of equal angles
Regular polygons
Think about …
What does ‘regular’ mean?
Think about
What is another name for a regular triangle?
What is another name for a regular quadrilateral?
Key words
regular
parallel
circle
perpendicular
triangles
scalene
acute-angled
quadrilaterals
parallelogram
rectangle
other polygons
pentagon
isosceles
right-angled
equilateral
obtuse-angled
trapezium
square
rhombus
kite
hexagon
octagon
Geometrical design
At the end of the activity
Name the different types of triangles.
Name each special type of quadrilateral.
List their properties.
What does the term 'regular' mean?
What is another name for a regular quadrilateral?
What types of jobs involve using geometrical shapes?
List as many as you can.