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- begin to identify
& use angle, side & symmetry properties
of triangles & quadrilaterals
and
- solve geometric problems, involving these properties,
using step-by-step deduction & explaining reasoning
with diagrams & text
- use 2-d representations to visualise 3-d shapes
& deduce some of their properties |
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shape
polygon:
regular
irregular
concave
convex
pentagon
hexagon
octagon
triangle:
equilateral
isosceles
scalene
right-angled
quadrilateral:
square
rectangle
rhombus
parallelogram
kite
arrowhead
delta
circle
2-dimensional, 2-d
3-dimensional, 3-d |
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1 Activities involving
visualisation & drawing of 2-d shapes (eg: p
184)
Eg: How many different shapes can you make from
overlapping 2 squares?
2 Activities involving visualisation & drawing
mainly of triangles & quadrilaterals (eg: p
186)
Eg: Use Logo to write instructions
to draw a rhombus OR plot visualised shapes, using:
Coordinate
Shapes from BGfL
3 Activities involving use of angle rules to solve
problems (eg: p 188) (see SSM2: angles a.a.p., on
a straight line, in a triangle, vertically opposite
angles)
Eg: 2 squares overlap so
a corner of the larger square is at the centre of
the smaller square. Explain why the overlapping
area is a quarter of the smaller square
4 Activities involving angle, side & symmetry
properties of triangles & quadrilaterals,
Eg: Pinboard Investigation
8 different triangles can
be constructed on a 3x3 pinboard. What are they?
Group them according to their angle, side &
symmetry properties. (See L1 plenary).
OR
For a review of and questions on angle and symmetry
properties of quadrilateral snad other polygons,
go to:
Bitesize
Shapes
For enrichment: How many times in 12 hours do the
hands of a clock make a right angle? Explore using
animated activity at:
Penta
Problem |
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Review
Angles:
Pinboard Investigation
There are 8 possible different triangles on a 3x3
pinboard. What are they?
(Discount reflections, rotations, translations)
How many have right angles?...
0, 1, 2 equal sides? 1, 2, 3 acute angles? 1 obtuse
angle?
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Review how to recognise
general reflection & rotational symmetry properties
of triangles & quadrilaterals (p 202)
Eg, OHS
SSM3/5: Symmetry in Shapes
...and use to solve geometric problems, eg: why
can you always make an isosceles triangle from 2
identical right-angled triangles? |
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Review
symmetry:
Pinboard Investigation
How many have 1/2/3 lines
of symmetry?
Do any have rotational
symmetry? Why? |
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reflect
reflection
reflection / line symmetry
line of symmetry
mirror line
rotate, rotation
rotational symmetry
symmetrical |
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| OHS
SSM3/6: Making Dice Pupils to label other 5
sides so when folded up, opposite sides total 7.
Check by folding. Use to highlight visualisation
aids for cubes. (Eg: shading basal face & mentally
folding Left then Right faces, Front then Back faces.
Top face last). |
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Activities involving
2-d representations of 3-d shapes & deducing
properties from them:
Eg 1 Guess the Shape
:
Given front & side elevation & plan view,
what is the 3-d shape?
Eg 2 Builder's Boss:
1 partner looks at a 2-d picture of a 3-d solid
& tells their partner how to build it.
Eg 3 Cubes Investigation:
Find all possible solids that can be made from 4
cubes. Record - isometric paper. Investigate different
numbers of cubes. |
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Cubes
Investigation
Collate & Compare results. Discuss systematic
approach.
Plan View? Front &
side elevation?
Which solid has minimum number of faces? Surface
Area? |
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