Scaled Drawings

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Scaled Drawings
National 4 REL 1.2b
Enlarging and Reducing Drawing
Working with Scales
Making Simple Scale Drawings
Harder Scale Drawings
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Compass Points Scale Drawings
Measuring Scales
Similar Shapes Scale Factor
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Starter Questions
National 4 REL 1.2b
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Enlarging Reducing
National 4 REL 1.2b
Learning Intention
Success Criteria
1. Be able to enlarge a shape by a factor.
1. To explain how to enlarge or reduce a given
shape by a factor.
2. Be able to reduce a shape by a factor.
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Double the size of the shape.
Enlarging Reducing
Half the size of the shape.
National 4 REL 1.2b
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Enlarging Reducing
National 4 REL 1.2b
Now try Ex 1 Q1 (e)(g)(i) (j) Q2 (c)(d)((g)(h)
Ch5 (page 50)
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Starter Questions
National 4 REL 1.2b
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Scales
National 4 REL 1.2b
Learning Intention
Success Criteria

1. To understand the term scale.

1. To explain the term scale on a map.
2. Calculate the real life distances using a
scaled.
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Scales
National 4 REL 1.2b
In order to make sense of a map or scale
diagram the scale must be known.
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Scales
National 4 REL 1.2b
In order to make sense of a map or scale
diagram the scale must be known.
For this scale model
1 cm represents 1m
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4 cm
This means for every 1 metre of the actual car,
1cm is drawn on the map.
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Scales
National 4 REL 1.2b
The scale of this drawing is 1cm 5m
6cm
What is the actual length of the tree ?
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30m
6 x 5
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Scales
National 4 REL 1.2b
The scale of this drawing is 1cm 90cm
What is the actual length of the bus in metres ?
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5cm
450cm
5 x 90
4.5m
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Scales
National 4 REL 1.2b
Now try Ex 2 Ch5 (page 52)
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Starter Questions
National 4 REL 1.2b
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Scaled Drawings
National 4 REL 1.2b
Learning Intention
Success Criteria
1. From information given make a scaled drawing.
1. To draw a scale drawing given suitable
information.
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Scaled Drawings
National 4 REL 1.2b
Problem
A garden is rectangular in shape and has length
12m and breadth 8m. Make rough sketch of the
garden.
12m
Draw an accurate scaled drawing of the
garden Use a scale of 1cm represents 2m
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8m
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Scaled Drawings
National 4 REL 1.2b
Use a scale of 1cm represents 2m
1cm represents 2m
12m
12m
8m
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8m
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Scaled Drawings
National 4 REL 1.2b
Problem
A road junction is triangular in shape. A rough
sketch is given below.
Draw an accurate scaled drawing of the
junction Use a scale of 1cm represents 2m
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20m
12m
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Scaled Drawings
National 4 REL 1.2b
Use a scale of 1cm represents 2m
1cm represents 2m
Find the real life length of the 3rd side
20m
20m
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12m
23.2m
2 x 11.6
12m
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Scaled Drawings
National 4 REL 1.2b
Now try Ex3 Ch5 (page 55)
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Starter Questions
National 4 REL 1.2b
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Drawing SAS Triangles
Aim of the Lesson
To construct a triangle given the length of two
sides and the included angle
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Drawing SAS Triangles
SAS Triangles
Side
Side
Angle
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Drawing SAS Triangles
Toolkit required
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Drawing SAS Triangles
C
30o
B
Example Draw to scale the triangle ABC with
AB 6cm and angle CAB 30o and AC 5cm
A
Step 1 Draw line AB6cm
Step 2 Measure angle CAB from A
C
X
Step 3 Draw the line AC 5cm through X. Label
it C.
A
B
Step 4 Join C to B.
Check angles add to 180o
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Scale Drawings
National 4 REL 1.2b
Now try Ex 4 Ch5 (page 58)
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Starter Questions
National 4 REL 1.2b
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Directions Scale Drawings
National 4 REL 1.2b
Learning Intention
Success Criteria
1. Be able to make sense of a map.

• To show how to write down directions using a map.
• 2. To explain how to construct a scale drawing
  using bearings.

• Write down accurate directions from a map.
• 3. Construct and interpret an accurate scale
  drawing.

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Compass Points
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If Gary walks to John then to Barry and then back
to where he started. Write down all the
directions he took.
If Anne walks to Julie then to Amy and then back
to where she started. Write down all the
directions she took.
If Daniel is facing North and turns clockwise to
face Anne. How many degrees is this.
If Daniel is facing Frances and turns clockwise
to face Amy. How many degrees is this.
If Amy is facing Paul and turns anti-clockwise to
face Daniel. How many degrees is this.
Who is North of Daniel
Who is East of John
Who is South West of Barry
Who is North East of Gary
Compass Points
National 4 REL 1.2b






Frances
John
Barry
N
Daniel
Julie
Anne
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Amy
Gary
Paul
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I leave the zoo to go back to my car which is in
the town car park. Write down the directions I
should take.
After going to the park I want to go to the
cinema. Tea Lane is closed. Write down the
directions I should take.
Theres a fire at the library. Right down the
directions the fire engine should take.
I come out of the swimming pool and turn right
then left. I go into the building second on my
the right. Name the building.
I come out of school and go to the Park. Write
down the directions I must take.
I come out of the charity shop and need to catch
a bus. Write down the directions to the bus
station.
Map Directions
National 4 REL 1.2b
N
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Scaled Drawings using Bearings
Make an accurate scale drawing of this sketch.
N
N
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50o
50o
15km
15km
1cm represents 3km
1cm represents 3km
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Scaled Drawings using Bearings
Make an accurate drawing of the plane journey
N
N
N
N
120o
120o
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45o
45o
8km
12km
12km
8km
1cm represents 2km
1cm represents 2km
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Compass points Scale Drawings
National 4 REL 1.2b
Now try Ex 5 Ch5 (page 61)
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Starter Questions
National 4 REL 1.2b
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Measuring Scales
National 4 REL 1.2b
Learning Intention
Success Criteria
1. Understand the connection between measuring
and scale.
1. To explain the connection between measuring
and scale.
2. Be able to do solve problems in context.
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Measuring Scales
National 4 REL 1.2b
Given that the scale of this drawing is 1cm
35cm
What is the actual length of the car in metres ?
10 x 35
350 cm
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3.5 m
? m
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Measuring Scales
National 4 REL 1.2b
Given that the scale of this drawing is 1cm
700cm
What is the actual height of the wind turbine in
metres ?
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? m
9 x 700
6300 cm
63 m
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Measuring Scales
National 4 REL 1.2b
Now try Extension Booklet Ex 6E Ch5 (page 19)
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Starter Questions
National 4 REL 1.2b
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Similar Shapes
National 4 REL 1.2b
Learning Intention
Success Criteria
1. Understand the words similar and factor.
1. To explain the meaning of the word
similar and factor in mathematics. Enlarge
and reduce similar shapes by a given factor.
2. Be able to enlarge / reduce a shape by a
given factor .
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Enlarging Reducing
National 4 REL 1.2b
Enlarged by a Scale Factor of two (Double)
These two photos are of the same view
3cm
1.5cm
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2cm
4cm
The second is double the size of the first.
The first could be ENLARGED to make the second.
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Enlarging Reducing
National 4 REL 1.2b
Reduced by a Scale Factor of a half
These two photos are of the same view
3cm
1.5cm
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2cm
4cm
The first is half the size of the second.
The second could be REDUCED to make the first.
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Similar Shapes
National 4 REL 1.2b
These two rectangles are similar.
4cm
2cm
4cm
8cm
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The first has been ENLARGED by a factor (ESF) of 2
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Find the missing length ? cm
Similar Rectangles
Find the enlargement factor
National 4 REL 1.2b
These two rectangles are similar.
?cm
2cm
4cm
12cm
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The first has been ENLARGED by a factor (ESF) of 3
? 2 x 3 6cm
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Find the missing length ? cm
Similar Rectangles
Find the reduction factor
National 4 REL 1.2b
These two rectangles are similar.
8cm
?cm
4cm
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16cm
The first has been ENLARGED by a factor (ESF) of 4
? 8 4 2cm
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Scale Factor applies to ANY SHAPES that are
mathematically similar.
7 cm
1.4 cm
2cm
y
z
3 cm
15 cm
6 cm
Given the shapes are similar, find the values y
and z ?
Scale factor
ESF
5
Scale factor
RSF
0.2
is 2 x 5 10
is 6 x 0.2 1.2
y
z
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Scale Factor applies to ANY SHAPES that are
mathematically similar.
Given the shapes are similar, find the values a
and b ?
Scale factor
RSF
0.4
Scale factor
ESF
2.5
is 8 x 0.4 3.2
is 2 x 2.5 5
a
b
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Scale factors
National 4 REL 1.2b
Enlargement Scale factor?
ESF

8cm
8
8
12
12cm
12
Reduction Scale factor?
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5cm

RSF
7.5cm
Can you see the relationship between the two
scale factors?
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Scale factors
National 4 REL 1.2b
Find a given ESF 3
ESF 3

9cm
a
27cm
By finding the RSF Find the value of b.
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b
5cm
RSF


15cm
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Scale factors
National 4 REL 1.2b
Now try Extension Booklet Ex 7E Ch5 (page 21)
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