Beforethetrail...ContourLinesontheMap
What are these wriggly lines on the map?
They have numbers on them.
80
60
100
120
40
20
Those are contour lines. The numbers on the contour lines
tells you the elevation, or height, along the contour lines.
Really? That sounds
very interesting.
Can you explain to me?
Sure! Let me show you an example. Come
and look at this model and its contour map.
Contour lines are lines drawn on a map connecting points
of the same height. For example, Point A has elevation
of 20 m. All the points on the red contour line which
passes through A also have the same height of 20 m.
●D
●C
80
60
40
20
100
120
●B
I understand now. At both B and C, the elevation
is 60 m. If we walk along the blue path,
the elevation will remain at 60 m.
●A
●D
●C
●B
●A
That’s right! And point D
is 120 m above sea level.
Let’s practise reading contour lines!
1. Look at the map. Write down the height at X, Y and Z.
140 Z
120
100
80
Y
Height at X = 20
X
m
Height at Y = 60 m
60
Height at Z = 140 m
40
20
2.If you move from X to Z,
you would have climbed 140 -
20 = 120 m.
3.If you move from Z to Y,
you would have descended 140 - 60 = 80 m.
4.Match the following terrains to the correct contour maps.
●
●
●
●
●
●
50
40
30
20
10
40
30
40
30
40
30
20
10
50
40
30
20
10
30
Are you ready to explore our
beautiful nature reserve?
YES!
Before we start, there are a few things
you must remember NOT to do.
Find out the meaning of the signs that you see in the reserve.
Do not feed any animal (including the monkeys).
Do not litter.
Do not kindle or cause any fires.
Do not damage, remove or collect any plant or
parts of plant.
Do not bring any animal (including dogs) into the
Reserves.
Do not capture any animal.
From The Park and Trees Act 2005
Sure, Mr One, we will remember all that.
Thanks for reminding us so that more people
will continue to enjoy this beautiful place.
Our first stop is Kruing Hut. Can you
find Kruing Hut on your map on page 2?
What is the height at Kruing Hut?
80
m
Estimate the height at your current location.
30
m
How high do you need to climb from here to the Kruing Hut?
80
-
30
=
50
m
How much higher is the summit than Kruing Hut?
163
-
80
=
83
m
As you walk to Kruing Hut, admire the many
species of plants and listen to the sound of the forest.
Let’s see if you can spot
the start of this fence.
From the first fence, use your stopwatch to find out how much time you took to walk from the first fence to Kruing Hut.
I took
2
minutes to walk from the first fence to Kruing Hut.
The fence is arranged in an interesting way.
Use the ruler
provided on
page 2 to
measure a fence.
1 fence
Walking speed up to Kruing Hut
There are 102 fences from the start of the fence to Kruing Hut.
Work out the distance from the start of the fence to Kruing Hut.
12 cm
Length of each fence = 162 cm - 12 cm
= 150 cm
Total length of fence= (150 cm x 102) + 12cm
= 15312 cm
= 153.12 m
162 cm
I took
2
minutes to walk from the first fence to Kruing Hut.
In one minute, I walked 151.12 m.
Your walking speed up the slope is 151.12 m in one minute.
Puzzle
Miss Three was on top of a hill and Master Four was at the foot of
the hill. They had to walk on a 720 m footpath to meet each other.
They started walking towards each other at the same time and
Miss Three was walking twice as fast as Master Four. How far did
Master Four walk before he met Miss Three?
0m
Miss Three
240 m
480 m
point they
will meet
From the diagram, Master Four walked 240 m.
720 m
Master Four
As we walk up to the summit, we are going to admire the wonders of nature.
If you divide a leaf in half, you will often find that
one half has the same shape as the other half.
That is the line of symmetry in leaves.
Can you spot these leaves? Can you see that the leaves are
symmetrical about a line? These leaves exhibit vein symmetry
and leaf-shape symmetry.
Paku Biawa
(Singaporeana)
Macaranga
bancana
Can you find 3 more leaves that are symmetrical?
Draw them below.
Piper sarmentosum
(Wild pepper)
Some leaves also have symmetrical leaf arrangements.
Santiria griffithii
Can you find another 2 symmetrical leaf arrangements?
Draw them below.
Making a simple symmetrical shape
1.Fold a piece of paper 2.Cut the folded paper
in half. The centre
into the shape of
line is the line of
half a leaf.
symmetry.
3.Unfold the paper
and you will get a
symmetrical leaf.
Try cutting these symmetrical shapes
(i) Flower
(ii) Diamond (iii) Hexagon
Take measurements of the steps to help you find the length
and height of the slope from the bottom of the steps to the
Summit Hut.
160 cm
120 cm
12 cm
1760 cm
Master Four found a deserted house along the trail. There is a treasure
map upstairs. But the stairs were broken. Help Master Four draw in the
steps so that he can go upstairs to get the map. Every step must be of
the same size.
Look! There are two tall radio
towers at the summit! Do you
know why they are fenced up?
Let’s look closer at the fence.
Wow! The fencing is made up
of many diamond shapes.
Can you measure the width and height of a diamond shape?
Give your answer to the nearest cm.
width
height
Width =
8.5 cm
Height = 8.5
cm
Area and Perimeter of the fence
Look at one face of the fence.
Can you estimate the
width and height of one
face of the fence?
Give your answer to the
nearest cm.
one face
My estimation:
Width =
33 x 8.5 = 280.5
width
cm
height
Height = 34 x 8.5 = 287 cm
Find the area of this face of the fence. Area =
280.5 x 287 x 18 sides
= 1449063
cm2.
Walk around the fencing.
Can you estimate the perimeter of the fencing to the nearest metre?
The perimeter is approximately =
10672
cm
You have found the area of one face of the fence. Master Four also
wanted to do the same. But instead of counting the diamond shapes,
he climbed up the fence and he accidentally damaged that face of
the fence. The police wanted him to pay for the fence, and the cost
of fencing is $5 per m2. The cost of labour is $50. How much would
Master Four have to pay to repair the damage?
1 m = 100 cm
1 m2 = 1 m x 1 m
= 100 cm x 100 cm
= 10000 cm2
1449063 cm2 = 144.9063 m2
Cost of fencing = 144.9063 x 5 = $724.53
Total cost = 725.53 + 50 = $775.53
Master Four would have to pay $775.53.
Polygons
Look! The fence around the radio tower has many sides.
A shape that is made up of straight sides is called a polygon.
(a) A polygon with 3 sides is called a triangle .
Do you see other 3-sided polygons at the summit?
Draw them in the boxes below.
Draw the line of symmetry if it is symmetrical.
roof
tower frame
rubbish bin
(b) A polygon with 4 sides is called a quadrilateral.
Do you see other 4-sided polygons at the summit?
Draw them in the boxes below.
Draw the line of symmetry if it is symmetrical.
roof
(view from front)
tower frame
Inside Summit
Hut Roof
(c) A polygon with 6 sides is called a hexagon .
Do you see other 6-sided polygons at the summit?
Draw them in the boxes below.
Draw the line of symmetry if it is symmetrical.
roof
(view from top)
signage