直角坐標系(一)8.3
8.1 直角坐標系簡介
A 位置
下圖所示為1A 班的座位表,每個 代表一個座位。座位排成
7 列( 即 第 1、2、g、7 列),而每列有 5 行( 即 第 1、2、g、5 行 )。
1
5
4
3
2
1
2 3 4 5 6 7
志明
小雯
行
列
黑板
家軒
愛玲
1. 小雯坐在第 5 列,第 2 行。
我們可用 (5 , 2) 來描述小雯的位置。
2. 利用同樣的方法描述志明、家軒和愛玲的位置。
列 行 位置
志明 1 3 ( , )
家軒
愛玲
課堂活動活動 8.1
趣味數學
以下是利用行和列來表示
座位的日常例子:
日D 月M 年Y
27/04/2019
4 P7
IIA
$140
2D 快樂家庭
新劍橋戲院
2D Happy FamilyStall - 140
CT-9035781-20190427
07:25 PM
時間 Time
片名 FILM
院 HOUSE 座位SEAT 票價/類別 PRICE/TYPE
級別 CAREGORY
N
戲票
登機證
在課堂活動 8.1 中,我們用行數和列數來描述位置。
T
2 3 4
U V W X S
S
8.0 基本知識重温(第 8.2 頁)
8.1 直角坐標系簡介(第 8.3 頁)
8.2 兩點之間的距離(第 8.14 頁)
8.3 多邊形的面積(第 8.25 頁)
8.4 點的變換(第 8.35 頁)
度量、圖形與空間範疇
直角坐標系(一)8
1B
建築物的位置
上圖顯示港鐵九龍塘站附近主要建築物的位置。我們可見又一城以 T2 來表示,
這是因為該建築物位於地圖上第 T 列和第 2 行的坐標方格內。
考考你 試利用一個字母和一個數字的組合來表示創新中心的位置。
6.4 Chapter 6
geometry 幾何 point 點 line 線 straight line 直線 curve 曲線 line segment 線段 end point 端點
6.1 Basic Concepts of Geometry
Geometry is a very important branch of Mathematics. In Geometry, we
mainly study shapes, sizes, positions of objects and the relations among
objects in space.
A Points, Lines and Surfaces
I. Points
A point is the simplest element in Geometry. It represents a position in
space and has no size. We usually represent a point by a small cross '✕'
or a small dot '•', and label it by a capital letter.
C
B
A
Points A, B and C
II. Lines and Line Segments
A line is made up of an infinite number of points. It has a length but has
no breadth. It can be extended in both directions without end.
There are two types of lines: straight lines and curves. We usually label a
line by a letter, e.g. L or l.
Straight line L Curve l
Note: For simplicity, all the lines mentioned in this book refer to
straight lines unless otherwise stated.
A line segment is a part of a straight line. It is named by the two end
points. Its length is equal to the distance between the two end points.
e.g. The figure shows a line segment AB (or BA).
Its length is 2 cm, which can be written as AB = 2 cm.
B
2 cm
A
Stars in the sky look like points
in Geometry.
Electrical wires look like lines
in Geometry.
More to Learn
A ray is a straight line with
one end point. It can be
extended without end in one
direction only.
Directed Numbers 2.31
Note: For simplicity, the '#' sign between the brackets can be omitted.
e.g. (i) (+8) # (-7) can be written as (+8)(-7) or 8(-7).
(ii) (-6) # (+3) # (-5) can be written as
(-6)(+3)(-5) or (-6)(3)(-5).
B Division of Directed Numbers
Consider the multiplication below:
(+10) # (+3) = +30
Since division is the reverse operation of multiplication, the above
operation can be rewritten as:
(+30) ' (+3) = +10
Here we can see that:
When a positive number is divided by a positive number,
the result is positive.
Let's explore the results of division involving negative numbers.
+10 +30
(+3)
(+3)
i.e. ()
()
3
30
+
+ = +10
◀
Evaluate the following expressions.
(a) (-3) # (+9) (b) (+4) # (-2)
(c) (+1) # (-2) # (+3) (d) (-8) # (-6) # (+3)
13
Instant Drill Challenge
Fill in each of the nine
boxes below with '2' or '-2'
so that the product of the
three numbers along each
column, each row and each
diagonal is 8.
➥ Ex 2C 1-4, 9
直角坐標系(一)8.3
8.1 直角坐標系簡介
A 位置
下圖所示為1A 班的座位表,每個 代表一個座位。座位排成
7 列( 即 第 1、2、g、7 列),而每列有 5 行( 即 第 1、2、g、5 行 )。
1
5
4
3
2
1
2 3 4 5 6 7
志明
小雯
行
列
黑板
家軒
愛玲
1. 小雯坐在第 5 列,第 2 行。
我們可用 (5 , 2) 來描述小雯的位置。
2. 利用同樣的方法描述志明、家軒和愛玲的位置。
列 行 位置
志明 1 3 ( , )
家軒
愛玲
課堂活動活動 8.1
趣味數學
以下是利用行和列來表示
座位的日常例子:
日D 月M 年Y
27/04/2019
4 P7
IIA
$140
2D 快樂家庭
新劍橋戲院
2D Happy FamilyStall - 140
CT-9035781-20190427
07:25 PM
時間 Time
片名 FILM
院 HOUSE 座位SEAT 票價/類別 PRICE/TYPE
級別 CAREGORY
N
戲票
登機證
在課堂活動 8.1 中,我們用行數和列數來描述位置。
Directed Numbers 2.31
Note: For simplicity, the '#' sign between the brackets can be omitted.
e.g. (i) (+8) # (-7) can be written as (+8)(-7) or 8(-7).
(ii) (-6) # (+3) # (-5) can be written as
(-6)(+3)(-5) or (-6)(3)(-5).
B Division of Directed Numbers
Evaluate the following expressions.
(a) (-3) # (+9) (b) (+4) # (-2)
(c) (+1) # (-2) # (+3) (d) (-8) # (-6) # (+3)
13
Instant Drill Challenge
Fill in each of the nine
boxes below with '2' or '-2'
so that the product of the
three numbers along each
column, each row and each
diagonal is 8.
➥ Ex 2C 1-4, 9
line 線 straight line 直線 curve 曲線 line segment 線段 end point 端點
Concepts of Geometry
ortant branch of Mathematics. In Geometry, we
es, positions of objects and the relations among
and Surfaces
element in Geometry. It represents a position in
e usually represent a point by a small cross '✕'
bel it by a capital letter.
C
B
A
Points A, B and C
Segments
infinite number of points. It has a length but has
ended in both directions without end.
nes: straight lines and curves. We usually label a
l.
aight line L Curve l
all the lines mentioned in this book refer to
less otherwise stated.
t of a straight line. It is named by the two end
l to the distance between the two end points.
line segment AB (or BA).
which can be written as AB = 2 cm.
B
2 cm
A
Stars in the sky look like points
in Geometry.
Electrical wires look like lines
in Geometry.
More to Learn
A ray is a straight line with
one end point. It can be
extended without end in one
direction only.
17
Book 1A Ch.2• P.2.31
Book 1A Ch.6• P.6.2
趣味數學
Interesting Maths
提供該章數學知識的應用事例。
知多一點 More to Learn
提供額外資料,包括實用網址和課外知識。
主題頁 Chapter Opener
加入日常生活題材
動腦筋 Challenge
提供較難題目,促進學生的思維。
1B冊 第8章 •
第8.3頁
1B冊 第8章 • 第8.1頁