Page 160 - MATHEMATICS COURSE FOR SECONDARY SCHOOLS BOOK 2
P. 160
Finding the actual measurement
scale measurements.
The height of Mini-me (from the second Austin Powers movie) is one-eighth of the
Finding the actual measurement
height of Dr Evil. If Dr Evil is 168 cm tall,
how tall is Mini-me?
The height of Mini-me (from the second
using the information from the second
Austin Powers movie) is one-eighth of the If your answer was 21 cm, then you are
scale measurements. sketch.
height of Dr Evil. If Dr Evil is 168 cm tall, correct.
using the information from the second
how tall is Mini-me?
EXAMPLE 2
This is a scale
If your answer was 21 cm, then you are
Example
drawing of a chair. correct.
Scale: 1 : 9
sketch.
What does it mean
1 During a visit to Japan, Sue Lyn made this sketch of a huge
This is a scale
Please if the scale is 1 : 9?
Example
drawing of a chair. supply
Scale: 1 : 9
sand sculpture.
this What is the actual
6 cm 6 cm
1
During a visit to Japan, Sue Lyn Using a scale of 1 cm to
What does it mean artwork height of the
made this sketch of a huge represent 3 m, make
Please
supply
this What is the actual
Please supply this artwork
if the scale is 1 : 9? chair?
sand sculpture.
a suitable scale
A scale of 1 : 9
drawing to find Using a scale of 1 cm to
artwork height of the
means that 1 unit
the height of represent 3 m, make
Please supply
chair?
of length on the
the tower in
a suitable scale o
drawing represents A scale of 1 : 9
the sand 50 drawing to find
horizontal
9 units of length in actual size. means that 1 unit
sculpture. the height of
15 m
this
of length on the } length in drawing
the tower in
drawing represents
9 units of length in actual size.
length in drawing } actual length
the sand
horizontal
1: 9
same units of length
15 m
ground
same units of length Thus, a sc1ale: o9f a : b means that a units of
the scale was given as 1 : 5. What is the
length on the drawing represent b units of actual length
actual length of the humming bird, if its
1 The given scale is 1 cm (on the drawing) length in the picture is 11.4 mm?
length in actual size.
to 3 m (on the sculpture).
Thus, a scale of a : b means that a units of If the scale is 1 : 9 and the length in the
So 3 m is represented by 1 cm.
The given scale is 1 cm (on the drawing)
to 3 m (on the sculpture). –1–5
15 m is represented by 3 × 1 cm = 5 cm.
So 3 m is represCented by 1 cm. 15 C
length on the drawing represent b units of drawing is 6 cm, then:
length in actual size.
length in drawing actual length
If the scale is 1 : 9 and the length in the
1 cm
9 cm
6 × 9 cm = 54 cm
9 × 6 cm = 54 cm.
To construct a scale drawing:
384 drawn.
measurements.
A
50o 15 m
B
A
o 50
Procedure
5 cm B
drawn.
The scale drawing looks like this.
To construct a scale drawing:
measurements.
154
2
1
actual length of the humming bird, if its Raymond found a picture of a humming
artwork 2 Raymond foundo a picture of a humming
50
bird in an encyclopaedia. On the picture
EXAMPLE 3
sculpture.
the scale was given as 1 : 5. What is the
length in the picture is 11.4 mm? bird in an encyclopaedia. On the picture
ground
drawing is 6 cm, then: 6 cm
15 m is represented by –– × 1 cm = 5 cm. 3
Please supply this artwork
length in drawing
actual length
Therefore, the actual height of the chair is
1 cm 9 cm o
9 × 6 cm = 54 cm.
6 cm 6 × 9 cm = 54 cm
C 15 m
50oC 5 cm
A 50
B
A
B
Please supply this artwork
Procedure
Therefore, the actual height of the chair is
The scale drawing looks like this.
384
