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SymmetrySymmetry
Line Symmetry
Rotational (Order) Symmetry
Translational Symmetry
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Creating Rotational Symmetry
MTH 2-19aMTH 3-19a
Starter QuestionsStarter Questionsw
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Q2. If 1 bar of chocolate costs 65p. How much will1000 bars cost. Give your answer in £’s.
(a) 4.56 (b) 7.254 (c) 9.244
Q3. Round to 1 decimal place
Q4. Convert to 24 hrs clock
(a) Half past 4 in the af ternoon.
(b) Quarter to eight in the morning.
MTH 2-19aMTH 3-19a
Line SymmetryLine Symmetryw
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1.1. Understand the term Understand the term line symmetry.line symmetry.
1. To revise line symmetry.
2.2. Complete Drawings Complete Drawings given the line of given the line of symmetry.symmetry.
MTH 2-19aMTH 3-19a
Line SymmetryLine Symmetryw
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A line symmetry occurs in a shape if, when the shape is folded over the line the two pieces either side of the line, are exactly the same.
MTH 2-19aMTH 3-19a
Line SymmetryLine SymmetryThe SquareThe Square
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MTH 2-19aMTH 3-19a
Line SymmetryLine SymmetryThe rectangleThe rectangle
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MTH 2-19aMTH 3-19a
Line SymmetryLine SymmetryThe squareThe square
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MTH 2-19aMTH 3-19a
Line SymmetryLine SymmetryThe RhombusThe Rhombus
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MTH 2-19aMTH 3-19a
Line SymmetryLine SymmetryThe ParallelogramThe Parallelogram
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No lines of symmetry !
MTH 2-19aMTH 3-19a
Line SymmetryLine SymmetryThe Equilateral TriangleThe Equilateral Triangle
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MTH 2-19aMTH 3-19a
Line SymmetryLine SymmetryThe Trapezium 1The Trapezium 1
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MTH 2-19aMTH 3-19a
Line SymmetryLine SymmetryThe Trapezium 2The Trapezium 2
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No lines of symmetry !
MTH 2-19aMTH 3-19a
Line SymmetryLine SymmetryThe HexagonalThe Hexagonal
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Line SymmetryLine Symmetryw
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MTH 2-19aMTH 3-19a
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Your turn !Exercise 1Page 81
Creating Half-TurnCreating Half-TurnSymmetrySymmetry
MTH 2-19aMTH 3-19a
Starter QuestionsStarter Questionsw
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Q2. What fraction is the green area. What fraction is the grey area.
Q3. A pencil costs 22p. How much doesa 1000 cost. Put your answer in £’s.
(a) 153.37 (b) 261.55
MTH 2-19aMTH 3-19a
Rotational Rotational SymmetrySymmetry
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1.1. Understand the terms Understand the terms rotational symmetry.rotational symmetry.
1. We are learning what rotational symmetry is for a shape.
MTH 2-19aMTH 3-19a
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Rotational SymmetryRotational Symmetry
This new shape has HALF - TURN symmetry
This dot is called the centre of symmetry
2. Use the tracing paper to make a copy of this shape.
3. Turn the tracing paper through 180 degrees about the dot.
1. Draw this shape into your jotter.
MTH 2-19aMTH 3-19a
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Rotation SymmetryRotation SymmetryHalf Turn Half Turn
All these shapes have order 2
MTH 2-19aMTH 3-19a
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Rotation SymmetryRotation SymmetryOrder Order
Has order 2
Has order 3
Has order 4
The order of symmetry is the number of times a shape looks the same in one complete turn.
MTH 2-19aMTH 3-19a
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Your turn !Exercise 2Page 82
Rotational Rotational SymmetrySymmetry
MTH 2-19aMTH 3-19a
Starter QuestionsStarter Questionsw
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Q4. Find the perimeter and area of the square.
Q3.
Q2. What is the time difference between 8.15am and 1:00pm
Solve 6y-16 20
Q5. Find the order of rotational symmetry for the shape opposite.
5cm
1
3 2
4
5 6
A=25cm2
P=20cm
MTH 2-19aMTH 3-19a
Creating Half-TurnCreating Half-TurnSymmetrySymmetry
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1.1. Understand the terms Understand the terms half-turn symmetry.half-turn symmetry.
1. We are learning how we can create half-turn symmetry for a shape.
2.2. Draw the other half of a Draw the other half of a shape such that it has shape such that it has half-turn symmetry.half-turn symmetry.
MTH 2-19aMTH 3-19a
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Creating Half-TurnCreating Half-TurnSymmetrySymmetry
Task 1Draw the complete shape you get
after it has been rotatedthrough 180 degrees about the point.
Task 2Do the same for this shape
MTH 2-19aMTH 3-19a
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Creating Half-TurnCreating Half-TurnSymmetrySymmetry
If you find it difficult to work out the new shape 1. Try tracing the shape first2. Then rotate tracing paper 180 deg about the point.
Task 3Do the same for this shape
MTH 2-19aMTH 3-19a
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Your turn !Exercise 3Page 85
Creating Half-TurnCreating Half-TurnSymmetrySymmetry
MTH 2-19aMTH 3-19a
Starter QuestionsStarter Questionsw
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133 % of £ 180
3Q1. Calculate
Q4. (-2) + (-3)
Q3.
Q2. What is the time difference between 8.15am and 1:00pm
Solve 2 4 20 x
Q5. How many lines of symmetry doesregular hexagon have.
MTH 2-19aMTH 3-19a
Translational Translational (slide)(slide)
SymmetrySymmetry
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1.1. Understand the terms Understand the terms translational, slide translational, slide congruent and tile.congruent and tile.
1. We are learning the meaning of Translational (slide) symmetry using tile patterns.
2.2. Identify shapes that tile.Identify shapes that tile.
3.3. Construct a tile pattern Construct a tile pattern for shapes.for shapes.
MTH 2-19aMTH 3-19a
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Translational Translational (slide)(slide)
SymmetrySymmetry
A shape that tiles can be completely surrounded by congruent shapes
WITHOUT leaving any gaps.
Exactlythe same
shape and size !
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Translational Translational (slide)(slide)
SymmetrySymmetry
Is this a tile pattern ?
No because there are
gaps
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Translational Translational (slide)(slide)
SymmetrySymmetry
Write down as many tile patterns as you canthat you see every day.
MTH 2-19aMTH 3-19a
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Your turn !Exercise 4Page 87
Translational Translational (slide)(slide)
SymmetrySymmetryMTH 2-19aMTH 3-19a
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