chapter 8 bearing.ppt
Transcript of chapter 8 bearing.ppt
North-west
South-east
South-west
North-east
NORTHWEST
EASTSOUTH
North does not always
have to point upright.
o Written in three-digits form (000� to 360� )o For angle less than 100� , add a zero in front
to write the bearing in three-digits.o Measure in angle in degrees clockwise from
the line pointing north.
55 ̊
A
N
B
Bearing of A from B is 055 ̊.
48 ̊ 32’
P
North
Q
48 ̊ 32’ = 48.5 ̊ Bearing of P from
Q is 048.5 ̊
a)b) Nort
h
Q42 ̊
P
South
180 ̊
180 ̊ + 42 ̊ =222 ̊Bearing of P from Q
is 222 ̊
Angles in degrees and minutes have to be converted
to degrees, correct to one decimal place.
Angles in degrees and minutes have to be converted
to degrees, correct to one decimal place.
North
Q43 ̊ 12’
P
South
43 ̊ 12’=43.2 ̊360 ̊ - 43.2 ̊ =316.8 ̊
Bearing of P from Q is 316.8 ̊
1̊ = 60’
2.060
12'12
An archaeologist knows that a treasure is buried at
a bearing of 150 ̊ from an old oak tree. He wants to draw on a map to help him remember its precise location.
In each of the following, find the bearing of point P from point Q given the bearing of point Q from point P is (a) 067 ̊ (b) 307 ̊
P
N
67 ̊ Q
N
67 ̊
Bearing of point P from point Q
180 ̊+ 67̊̊ = 247̊̊
P
N
307 ̊Q
N
Ө
Bearing of point P from point Q
Ө = 307̊ ̊ - 180 ̊= 127̊ ̊
In the diagram, point P is due east of point Q. Find the bearing of (a) R from Q (b) R from P
Bearing of R from Q= 90 ̊ +67 ̊=157 ̊
N
N
N
N
Bearing of R from P= 360 ̊ - 90 ̊ - 78 ̊ = 192 ̊
783567180QPR
N
50 ̊
(a) Bearing of P from Q 180 ̊ + 50 ̊ =230̊
N
44 ̊
44 ̊
(b) Bearing of P from Q 224 ̊ - 180 ̊ =44̊
N
134 ̊
(c) Bearing of P from Q 180 ̊ + 134 ̊ = 314̊
A man in a boat saw a lighthouse at a bearing 056 . ̊What was the bearing of the boat as seen by a guard in the lighthouse? If a camper on the beach saw the boat at a bearing of 290 ,what would the bearing of the camper be ̊from the boat?
56 �
Lighthouse
Boat56 �
Lighthouse
Boat
56 �
180 �
N
N
N
Bearing of the lighthouseFrom the boat =056 ̊
Bearing of the boat from The lighthouse=180 ̊+ 56 ̊
=236 ̊
34 ̊
B
A
NN
124 ̊
C
N34 ̊ 56 ̊
56 ̊
AB=20kmBC=50km
2.6820
50tan
20
50tan)(
1
BAC
BAC
BACa
68.2 ̊
Bearing of C from A 34 ̊ + 68.2 ̊ =102.2 ̊
kmACAC
ACb
85.532900
5020)( 222
A fisherman set out from a fishing village A to fishing ground B, 20 km away at a bearing of 034̊. After the catch, the fishermanwent to sell his fish in town C, 50 km from B at a bearing of 124̊. Find(a) the bearing of C from A (b) Distance AC
1. The bearing of Ben’s house from Ahmad’s house is 075 � whereas the bearing of Chin’s house from Ahmad’s house is 105 ̊ . Given that Ben’s house and Chin’s house are both 150 m from Ahmad’s house, find (a) the bearing of Ben’s house from Chin’s house. (b) the distance between Ben’s and Chin’s house.
2. In the treasure hunt, a scout has to move 400 m at a bearing of 146 ̊ from the base camp to find a key. After getting the key, he has to move 300 m at a bearing of 056 ̊ to a treasure chest. Find(a)the bearing of the treasure chest from the base camp.(b)the distance of the treasure chest from the base camp.
Ahmad
N
Ben
Chin
75 ̊
150 m
105 ̊ 30 ̊
150 m
(a)Bearing of Ben’s house from Chin’s house.
000�
(b) Distance between Ben’s and Chin’s house.
x
x
mxxxxx
x
65.7726457.772
)8229.38(228229.38
15sin150150
15sin
Distance between Ben’s and Chin’s house =77.65 m
Basecamp
N
Key
400 m
146 ̊
N
Treasurechest
300 m56 ̊
146 ̊
34 ̊
(a)Bearing of the treasure chest from the base camp.
9.364
3tan
400
300tan
1
x
x
x
Bearing of the treasure chestfrom the base camp = 146̊ - 36.9̊ = 109.1 ̊
Basecamp
N
Key
400 m
146 ̊
N
Treasurechest
300 m56 ̊
146 ̊
34 ̊
(b) Distance of the treasure chest from the base camp.
Use Pythagoras theorem
Distance of the treasure chest from the base camp = 500 m