Bearings GCSE Exam question ples help
$begingroup$
A ship sails 12km on a bearing of 050 degrees then 20km on a bearing of 100 degrees. It then sails directly back to its starting position. Calculate this distance to 1dp.
What i did:
I got the distance as 23 which is wrong idk y.
I just measured the distance.
Thank You and Help is appreciated
geometry
asked Dec 8 '18 at 15:47
xx_Gcsemathstudent_xxxx_Gcsemathstudent_xx
356
$endgroup$
|
show 8 more comments
$begingroup$
A ship sails 12km on a bearing of 050 degrees then 20km on a bearing of 100 degrees. It then sails directly back to its starting position. Calculate this distance to 1dp.
What i did:
I got the distance as 23 which is wrong idk y.
I just measured the distance.
Thank You and Help is appreciated
geometry
asked Dec 8 '18 at 15:47
xx_Gcsemathstudent_xxxx_Gcsemathstudent_xx
356
$endgroup$
$begingroup$
It would help it you show your calculations. How can you expect us to tell you what you did wrong if you don't show us what you did?
$endgroup$
– saulspatz
Dec 8 '18 at 15:52
$begingroup$
I just measured the distance and drew bearings.
$endgroup$
– xx_Gcsemathstudent_xx
Dec 8 '18 at 15:54
$begingroup$
You mean you drew a picture and measured the segment with a ruler? That won't be accurate enough. Besides, I'm sure you are expected to solve the problem with trigonometry. Go back over your lessons.
$endgroup$
– saulspatz
Dec 8 '18 at 15:56
$begingroup$
Ohhhhh ok I just wanted to check if the bearing shape is right?
$endgroup$
– xx_Gcsemathstudent_xx
Dec 8 '18 at 15:58
$begingroup$
Well, the angles are all right. (I mean the numbers, I have no way of actually measuring the angles) and if the line length are $12$ and $20$ then you are right. What is the answer supposed to be?
$endgroup$
– saulspatz
Dec 8 '18 at 16:00
|
show 8 more comments
$begingroup$
A ship sails 12km on a bearing of 050 degrees then 20km on a bearing of 100 degrees. It then sails directly back to its starting position. Calculate this distance to 1dp.
What i did:
I got the distance as 23 which is wrong idk y.
I just measured the distance.
Thank You and Help is appreciated
geometry
asked Dec 8 '18 at 15:47
xx_Gcsemathstudent_xxxx_Gcsemathstudent_xx
356
$endgroup$
A ship sails 12km on a bearing of 050 degrees then 20km on a bearing of 100 degrees. It then sails directly back to its starting position. Calculate this distance to 1dp.
What i did:
I got the distance as 23 which is wrong idk y.
I just measured the distance.
Thank You and Help is appreciated
geometry
geometry
asked Dec 8 '18 at 15:47
xx_Gcsemathstudent_xxxx_Gcsemathstudent_xx
356
asked Dec 8 '18 at 15:47
xx_Gcsemathstudent_xxxx_Gcsemathstudent_xx
356
edited Dec 8 '18 at 15:54
xx_Gcsemathstudent_xx
asked Dec 8 '18 at 15:47
xx_Gcsemathstudent_xxxx_Gcsemathstudent_xx
356
asked Dec 8 '18 at 15:47
xx_Gcsemathstudent_xxxx_Gcsemathstudent_xx
356
asked Dec 8 '18 at 15:47
xx_Gcsemathstudent_xxxx_Gcsemathstudent_xx
356
356
$begingroup$
It would help it you show your calculations. How can you expect us to tell you what you did wrong if you don't show us what you did?
$endgroup$
– saulspatz
Dec 8 '18 at 15:52
$begingroup$
I just measured the distance and drew bearings.
$endgroup$
– xx_Gcsemathstudent_xx
Dec 8 '18 at 15:54
$begingroup$
You mean you drew a picture and measured the segment with a ruler? That won't be accurate enough. Besides, I'm sure you are expected to solve the problem with trigonometry. Go back over your lessons.
$endgroup$
– saulspatz
Dec 8 '18 at 15:56
$begingroup$
Ohhhhh ok I just wanted to check if the bearing shape is right?
$endgroup$
– xx_Gcsemathstudent_xx
Dec 8 '18 at 15:58
$begingroup$
Well, the angles are all right. (I mean the numbers, I have no way of actually measuring the angles) and if the line length are $12$ and $20$ then you are right. What is the answer supposed to be?
$endgroup$
– saulspatz
Dec 8 '18 at 16:00
|
show 8 more comments
$begingroup$
It would help it you show your calculations. How can you expect us to tell you what you did wrong if you don't show us what you did?
$endgroup$
– saulspatz
Dec 8 '18 at 15:52
$begingroup$
I just measured the distance and drew bearings.
$endgroup$
– xx_Gcsemathstudent_xx
Dec 8 '18 at 15:54
$begingroup$
You mean you drew a picture and measured the segment with a ruler? That won't be accurate enough. Besides, I'm sure you are expected to solve the problem with trigonometry. Go back over your lessons.
$endgroup$
– saulspatz
Dec 8 '18 at 15:56
$begingroup$
Ohhhhh ok I just wanted to check if the bearing shape is right?
$endgroup$
– xx_Gcsemathstudent_xx
Dec 8 '18 at 15:58
$begingroup$
Well, the angles are all right. (I mean the numbers, I have no way of actually measuring the angles) and if the line length are $12$ and $20$ then you are right. What is the answer supposed to be?
$endgroup$
– saulspatz
Dec 8 '18 at 16:00
$begingroup$
It would help it you show your calculations. How can you expect us to tell you what you did wrong if you don't show us what you did?
$endgroup$
– saulspatz
Dec 8 '18 at 15:52
$begingroup$
It would help it you show your calculations. How can you expect us to tell you what you did wrong if you don't show us what you did?
$endgroup$
– saulspatz
Dec 8 '18 at 15:52
$begingroup$
I just measured the distance and drew bearings.
$endgroup$
– xx_Gcsemathstudent_xx
Dec 8 '18 at 15:54
$begingroup$
I just measured the distance and drew bearings.
$endgroup$
– xx_Gcsemathstudent_xx
Dec 8 '18 at 15:54
$begingroup$
You mean you drew a picture and measured the segment with a ruler? That won't be accurate enough. Besides, I'm sure you are expected to solve the problem with trigonometry. Go back over your lessons.
$endgroup$
– saulspatz
Dec 8 '18 at 15:56
$begingroup$
You mean you drew a picture and measured the segment with a ruler? That won't be accurate enough. Besides, I'm sure you are expected to solve the problem with trigonometry. Go back over your lessons.
$endgroup$
– saulspatz
Dec 8 '18 at 15:56
$begingroup$
Ohhhhh ok I just wanted to check if the bearing shape is right?
$endgroup$
– xx_Gcsemathstudent_xx
Dec 8 '18 at 15:58
$begingroup$
Ohhhhh ok I just wanted to check if the bearing shape is right?
$endgroup$
– xx_Gcsemathstudent_xx
Dec 8 '18 at 15:58
$begingroup$
Well, the angles are all right. (I mean the numbers, I have no way of actually measuring the angles) and if the line length are $12$ and $20$ then you are right. What is the answer supposed to be?
$endgroup$
– saulspatz
Dec 8 '18 at 16:00
$begingroup$
Well, the angles are all right. (I mean the numbers, I have no way of actually measuring the angles) and if the line length are $12$ and $20$ then you are right. What is the answer supposed to be?
$endgroup$
– saulspatz
Dec 8 '18 at 16:00
|
show 8 more comments
1 Answer
1
active
oldest
votes
$begingroup$
Use the cosine law: if $a$, $b$, $c$ are the sides of a triangle opposite to angles $A$, $B$, $C$ then
$$a^2=b^2+c^2-2bccos A\b^2=a^2+c^2-2accos B\c^2=a^2+b^2-2abcos C$$
In your case $a=20$, $c=12$ and $B=130^{circ}$ so you can use the second equation to find $b$.
answered Dec 8 '18 at 17:10
BPPBPP
2,169927
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1 Answer
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active
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1 Answer
1
active
oldest
votes
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oldest
votes
active
oldest
votes
$begingroup$
Use the cosine law: if $a$, $b$, $c$ are the sides of a triangle opposite to angles $A$, $B$, $C$ then
$$a^2=b^2+c^2-2bccos A\b^2=a^2+c^2-2accos B\c^2=a^2+b^2-2abcos C$$
In your case $a=20$, $c=12$ and $B=130^{circ}$ so you can use the second equation to find $b$.
answered Dec 8 '18 at 17:10
BPPBPP
2,169927
$endgroup$
add a comment |
$begingroup$
Use the cosine law: if $a$, $b$, $c$ are the sides of a triangle opposite to angles $A$, $B$, $C$ then
$$a^2=b^2+c^2-2bccos A\b^2=a^2+c^2-2accos B\c^2=a^2+b^2-2abcos C$$
In your case $a=20$, $c=12$ and $B=130^{circ}$ so you can use the second equation to find $b$.
answered Dec 8 '18 at 17:10
BPPBPP
2,169927
$endgroup$
add a comment |
$begingroup$
Use the cosine law: if $a$, $b$, $c$ are the sides of a triangle opposite to angles $A$, $B$, $C$ then
$$a^2=b^2+c^2-2bccos A\b^2=a^2+c^2-2accos B\c^2=a^2+b^2-2abcos C$$
In your case $a=20$, $c=12$ and $B=130^{circ}$ so you can use the second equation to find $b$.
answered Dec 8 '18 at 17:10
BPPBPP
2,169927
$endgroup$
Use the cosine law: if $a$, $b$, $c$ are the sides of a triangle opposite to angles $A$, $B$, $C$ then
$$a^2=b^2+c^2-2bccos A\b^2=a^2+c^2-2accos B\c^2=a^2+b^2-2abcos C$$
In your case $a=20$, $c=12$ and $B=130^{circ}$ so you can use the second equation to find $b$.
answered Dec 8 '18 at 17:10
BPPBPP
2,169927
answered Dec 8 '18 at 17:10
BPPBPP
2,169927
answered Dec 8 '18 at 17:10
BPPBPP
2,169927
answered Dec 8 '18 at 17:10
BPPBPP
2,169927
2,169927
add a comment |
add a comment |
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$begingroup$
It would help it you show your calculations. How can you expect us to tell you what you did wrong if you don't show us what you did?
$endgroup$
– saulspatz
Dec 8 '18 at 15:52
$begingroup$
I just measured the distance and drew bearings.
$endgroup$
– xx_Gcsemathstudent_xx
Dec 8 '18 at 15:54
$begingroup$
You mean you drew a picture and measured the segment with a ruler? That won't be accurate enough. Besides, I'm sure you are expected to solve the problem with trigonometry. Go back over your lessons.
$endgroup$
– saulspatz
Dec 8 '18 at 15:56
$begingroup$
Ohhhhh ok I just wanted to check if the bearing shape is right?
$endgroup$
– xx_Gcsemathstudent_xx
Dec 8 '18 at 15:58
$begingroup$
Well, the angles are all right. (I mean the numbers, I have no way of actually measuring the angles) and if the line length are $12$ and $20$ then you are right. What is the answer supposed to be?
$endgroup$
– saulspatz
Dec 8 '18 at 16:00