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okay! here goes nothing...
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welkx
npwelkx
srry fom the poor editing
THANK YOUU ^_^Did I mention?
http://upload.wikimedia.org/wikiped...Circle_slices.svg/220px-Circle_slices.svg.png
The purple thingy is called a segment…
The line at the base of the segment is called a chord…
Any line cutting the circle right from the middle aill be its diameter…
Any line cutting the circle from other than the middle is called a chord…
Length of chord…
http://www.thestudentroom.co.uk/attachment.php?attachmentid=103654&d=1306864631
Q.1. Find the length of chord?
Ans
By using cosine rule
http://s3.amazonaws.com/rapgenius/1364467873_cosine_rule.jpg
(Ac)²= a²+b² -2bc cos Õ
(Ac)²= (10.4²)+(10.4²)–2(10.4)(10.4)cos (2π/3)
(Ac)²=216.32–(–108.16)
(Ac)²= 324.48
Area of a segment…
There is no specific formula for this ul just have to pay with the geometry of a circle….
Now consider my words when I say… When I substract the areaof a triangle from the area of a sector I get the area of a segment…
That is
0.5 (r²) (Õ)–(0.5*base*h )= area of segment.
Example
http://www.thestudentroom.co.uk/attachment.php?attachmentid=103654&d=1306864631
Q.1. Find the area of segment ABC?
Ans.
I substract the areaof a triangle from the area of a sector I get the area of a segment…
(120/180)π= 2π/3
Area of segment=
0.5 (r²) (Õ)–(0.5*base*h )= area of segment.
Area of sector=
0.5 (r²) (Õ)
0.5(10.4 ²)(2π/3) cm²
36.05π
Area of triangle=
0.5 absinc an alternate formula as its short.
0.5 (10.4)(10.4) sin (2π/3)
46.83 cm²
36.05π – 46.83= 66.42 cm²
Perimeter of a segment…
This would consist of an arc length + the length of chord.
Example
http://www.thestudentroom.co.uk/attachment.php?attachmentid=103654&d=1306864631
Q.1. Find the perimeter iof the segment.
Ansd. Length Ac + S
Ac as above= 14.7cm
S=rÕ
S10.4*2π/3
S=21.8
14.7 +21.8= 36.5 cm.
Additional note…
*Area of sector/ area of the entire circle =
angle of the sector/ angle of the entire circle.
http://www.1728.org/circpart.htm
had adddmaths here too. p1 and p3 become so easy naturallynice (Y) though I had addmaths so this was never a problem for me always thought it was a mark gainer . ddmaths questions were way tougher -____- (cie logic :/)
nope P3 is much hader but yeah it comes naturally am actually enjoying p3 the key here is though : how to kill the idiot who invented complex nos -______-had adddmaths here too. p1 and p3 become so easy naturally
i think addmaths was tougher than the p1 and p3 combined
I KNOWWWWWWWWWWWWWWWWWWWWWWnope P3 is much hader but yeah it comes naturally am actually enjoying p3 the key here is though : how to kill the idiot who invented complex nos -______-
our maths sir said i dont have tym.nope P3 is much hader but yeah it comes naturally am actually enjoying p3 the key here is though : how to kill the idiot who invented complex nos -______-
you cant blv tbut we have a lot of darned ill logical theory to study now :'(nope P3 is much hader but yeah it comes naturally am actually enjoying p3 the key here is though : how to kill the idiot who invented complex nos -______-
I plan to do chemical engineering so maths is their but in fewer ammountyou cant blv tbut we have a lot of darned ill logical theory to study now :'(
pages and pages...
imagine having to rote learn
all the wordings
http://en.wikipedia.org/wiki/Vector_space
Its not the concepts i find hard its the application of those concepts if you solve 10 years you solve atleast 16 different types of questions -___- I mean who does that :/our maths sir said i dont have tym.
we pleaded.
he said i have sunday
we said ok
he said 8 am
we said ok
he said three hours we said ok.
when we came out of that class we knew complex numbers...
you guys need to learn this? its the easiest of all topics (in Add maths) 0.0Did I mention?
http://upload.wikimedia.org/wikiped...Circle_slices.svg/220px-Circle_slices.svg.png
The purple thingy is called a segment…
The line at the base of the segment is called a chord…
Any line cutting the circle right from the middle aill be its diameter…
Any line cutting the circle from other than the middle is called a chord…
Length of chord…
http://www.thestudentroom.co.uk/attachment.php?attachmentid=103654&d=1306864631
Q.1. Find the length of chord?
Ans
By using cosine rule
http://s3.amazonaws.com/rapgenius/1364467873_cosine_rule.jpg
(Ac)²= a²+b² -2bc cos Õ
(Ac)²= (10.4²)+(10.4²)–2(10.4)(10.4)cos (2π/3)
(Ac)²=216.32–(–108.16)
(Ac)²= 324.48
Area of a segment…
There is no specific formula for this ul just have to pay with the geometry of a circle….
Now consider my words when I say… When I substract the areaof a triangle from the area of a sector I get the area of a segment…
That is
0.5 (r²) (Õ)–(0.5*base*h )= area of segment.
Example
http://www.thestudentroom.co.uk/attachment.php?attachmentid=103654&d=1306864631
Q.1. Find the area of segment ABC?
Ans.
I substract the areaof a triangle from the area of a sector I get the area of a segment…
(120/180)π= 2π/3
Area of segment=
0.5 (r²) (Õ)–(0.5*base*h )= area of segment.
Area of sector=
0.5 (r²) (Õ)
0.5(10.4 ²)(2π/3) cm²
36.05π
Area of triangle=
0.5 absinc an alternate formula as its short.
0.5 (10.4)(10.4) sin (2π/3)
46.83 cm²
36.05π – 46.83= 66.42 cm²
Perimeter of a segment…
This would consist of an arc length + the length of chord.
Example
http://www.thestudentroom.co.uk/attachment.php?attachmentid=103654&d=1306864631
Q.1. Find the perimeter iof the segment.
Ansd. Length Ac + S
Ac as above= 14.7cm
S=rÕ
S10.4*2π/3
S=21.8
14.7 +21.8= 36.5 cm.
Additional note…
*Area of sector/ area of the entire circle =
angle of the sector/ angle of the entire circle.
http://www.1728.org/circpart.htm
llollyou guys need to learn this? its the easiest of all topics (in Add maths) 0.0
lol?lloll
yuplol?
why?
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