# Product Design A Level maths questionWatch

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Thread starter 2 weeks ago
#1
I’m a bit stuck on this question can someone help.
Last edited by Anonymous_4657; 2 weeks ago
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Thread starter 2 weeks ago
#2
Last edited by Anonymous_4657; 2 weeks ago
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2 weeks ago
#3
Have you attempted it? If so, what have you done so far?
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Thread starter 2 weeks ago
#4
(Original post by JSG29)
Have you attempted it? If so, what have you done so far?
I found the diameter of semi circle using cos (60) = Opposite / 48
Last edited by Anonymous_4657; 2 weeks ago
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Thread starter 2 weeks ago
#5
(Original post by JSG29)
Have you attempted it? If so, what have you done so far?
Is this right so far? I asked someone and he said use tan. Where does tan come from?
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2 weeks ago
#6
The diameter of the semicircle is just 48. You need to use tan for the bottom part - look at the diagram in 3 parts; the triangle at the bottom, the next rectangle and then the semicircle at the top. You already know the length of the rectangle (55), you can find the length from the triangle using the width of the strip (48) and tan, and the length from the semicircle is its radius.
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Thread starter 2 weeks ago
#7
(Original post by JSG29)
The diameter of the semicircle is just 48. You need to use tan for the bottom part - look at the diagram in 3 parts; the triangle at the bottom, the next rectangle and then the semicircle at the top. You already know the length of the rectangle (55), you can find the length from the triangle using the width of the strip (48) and tan, and the length from the semicircle is its radius.
I don’t get it. Can you draw this out for me please
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Thread starter 2 weeks ago
#8
(Original post by JSG29)
The diameter of the semicircle is just 48. You need to use tan for the bottom part - look at the diagram in 3 parts; the triangle at the bottom, the next rectangle and then the semicircle at the top. You already know the length of the rectangle (55), you can find the length from the triangle using the width of the strip (48) and tan, and the length from the semicircle is its radius.
Could you not use cos?
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2 weeks ago
#9
As mentioned above, you need to add on two bits to 55
* The radius of the large semicircle at the top
* The extra triangle at the bottom

Which bit are you stuck with?
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Thread starter 2 weeks ago
#10
(Original post by mqb2766)
As mentioned above, you need to add on two bits to 55
* The radius of the large semicircle at the top
* The extra triangle at the bottom

Which bit are you stuck with?
Why do you use tan? And for the length do you you use half of the circumference of semi circle plus length of triangle plus length of rectangle.
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2 weeks ago
#11
(Original post by Anonymous_4657)
Why do you use tan? And for the length do you you use half of the circumference of semi circle plus length of triangle plus length of rectangle.
? You want to calculate the length of the piece of metal. The width is 48 and the length is
55 + bit at top + bit at bottom
Do you understand this? I can't see where the circumference of the semicircle is important.
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Thread starter 2 weeks ago
#12
(Original post by mqb2766)
? You want to calculate the length of the piece of metal. The width is 48 and the length is
55 + bit at top + bit at bottom
Do you understand this? I can't see where the circumference of the semicircle is important.
No. Please may you show your workings. I just don’t know what measurements you need for the length. I just don’t understand. 😪 I do A Level maths as well.
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2 weeks ago
#13
(Original post by Anonymous_4657)
No. Please may you show your workings. I just don’t know what measurements you need for the length. I just don’t understand. 😪 I do A Level maths as well.
Sorry, the forum guidelines are that we don't do solutions.

If you rotate the bar round an additional 40 degrees (anticlockwise), the width is the x-direction and the length is the y direction which is
55 + "triangle" at bottom + semicircle at top
You can draw or cut out the shape and understand that.
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Thread starter 2 weeks ago
#14
(Original post by mqb2766)
Sorry, the forum guidelines are that we don't do solutions.

If you rotate the bar round an additional 40 degrees (anticlockwise), the width is the x-direction and the length is the y direction which is
55 "triangle" at bottom semicircle at top
You can draw or cut out the shape and understand that.
Ok. I though the 48 was the length of slanted line. What is the answer?
Last edited by Anonymous_4657; 2 weeks ago
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2 weeks ago
#15
(Original post by Anonymous_4657)
Ok. I though the 48 was the length of slanted line.
No its the width of the bar. Are you ok with the other parts?
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Thread starter 2 weeks ago
#16
(Original post by mqb2766)
No its the width of the bar. Are you ok with the other parts?
What bits do you need to add up to get the length of steel strip needed.
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2 weeks ago
#17
(Original post by Anonymous_4657)
What bits do you need to add up to get the length of steel strip needed.
Please read #13 or #11 or ...
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Thread starter 2 weeks ago
#18
(Original post by mqb2766)
Please read #13 or #11 or ...
Why do you add all the bit at the bottom and top?
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Thread starter 2 weeks ago
#19
(Original post by mqb2766)
Please read #13 or #11 or ...
I still don’t get it. I think I’m just going to leave it and fail my a level design
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2 weeks ago
#20
(Original post by Anonymous_4657)
I still don’t get it. I think I’m just going to leave it and fail my a level design
If you cut it out and rotate it 40 degrees (anticlockwise) so that the length is the height, it should be obvious.
Even if you do it and can't work something out, upload an image of what you've done.
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