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#101 2010-05-23 22:31:04

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Area problems Please Help!!

The angle is 120 degrees. And 4 is the... radius?

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#102 2010-05-23 22:32:43

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Area problems Please Help!!

No 240 degrees of the circle is in the area you don't want. How much is in the area you do.

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#103 2010-05-23 22:41:03

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Area problems Please Help!!

Oh so out of 360, 120 of it is what I want and the other 240 of it I don't?

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#104 2010-05-23 22:43:59

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Area problems Please Help!!

120 degrees is 1/ 3 of 360 degrees. So you want 1/3 of the area of that circle. Area of a circle is:

A = π r^2

A = π 16 you want 1 / 3 of that

A of shaded region = ( 16 π ) / 3

providing that the problem is stating that the radius is 4.

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#105 2010-05-23 22:49:36

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Area problems Please Help!!

Okay so I kinda see how you did that, so is say we used the same circle but changed the angle to.. say 90 degrees and the radius to like 8 then the answer would be:

A = (64 π) / 4 ?

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#106 2010-05-23 22:51:10

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Area problems Please Help!!

Yes if the area you were interested in was 90 degrees with a radius of 8. That is correct.

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#107 2010-05-23 22:57:33

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Area problems Please Help!!

Okay so what about something like this:

Find the difference in area between the large circle and the small circle

*its one of the shady in ones, so in order to o this do we find the area for both?

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#108 2010-05-23 22:59:07

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Area problems Please Help!!

36 π - 9π = 27 π

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#109 2010-05-23 23:04:10

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Area problems Please Help!!

Do you have work for that? Can I see it if you do?

I'm really sorry, my comprehension l;evels are really low atm, I am exetremely tired and I can't go to bed till I finish this..

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#110 2010-05-23 23:10:21

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Area problems Please Help!!

Area of the big circle = 6*6 * π = 36 π

Area of the little circle = 3 *3 π = 9 π

Difference ( means subtract ) between large circle and small circle 36 π - 9π = 27 π

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#111 2010-05-23 23:12:27

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Area problems Please Help!!

Okay so I have another on like this. Do you think you can try and walk my slow self through this one? (I feel like a moron right now)

okay same thing: Find the difference in area between the circle and the square

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#112 2010-05-23 23:14:32

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Area problems Please Help!!

Area of the square = (2 √ 2 ) ^2 = 4 * 2 = 8

and the segments are 90 degrees. Do you understand so far?

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#113 2010-05-23 23:17:03

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Area problems Please Help!!

okay. Area of the square is 8.

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#114 2010-05-23 23:20:50

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Area problems Please Help!!

The diagonals of the square are the same as the diameter of the circle. So using pythagoras

r^2 + r^2 = (2 √ 2 ) ^2

2 r^2 = 8

r^2 = 4

r = 2

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#115 2010-05-23 23:24:09

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Area problems Please Help!!

So now that we know the radius we can us it to find the area!

So A= πr ²

    A= π2 ²

    A= 4π?

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#116 2010-05-23 23:26:46

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Area problems Please Help!!

Take the area of the square away from that.

4π - 8, Hey that might be right. What do you think.

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#117 2010-05-23 23:28:10

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Area problems Please Help!!

Sure looks like it, wow I  was actually able to follow you on that one!

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#118 2010-05-23 23:34:28

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Area problems Please Help!!

Cool, beddie bye time. As me Daddy used to say, before he would beat me senseless, "Bed,bed or a shot in the head."

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#119 2010-05-23 23:39:33

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Area problems Please Help!!

Wait! Just two more please!!! Then you can shoot me!

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#120 2010-05-23 23:40:31

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Area problems Please Help!!

1 more!

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#121 2010-05-23 23:50:25

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Area problems Please Help!!

Okay okay!!!! I'm sorry! Your making me feel so guilty now!! DX

Here: Find the combined area of the triangles

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#122 2010-05-23 23:59:04

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Area problems Please Help!!

That is a small diagram, did they run out of ink? That hypotenuse is given as the diameter, yes?

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#123 2010-05-24 00:00:06

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Area problems Please Help!!

LOL maabe they did.

And yeah i think so.

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#124 2010-05-24 00:04:15

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Area problems Please Help!!

See that triangle. It is a 30 60 90 triangle. By sohcahtoa, the side opposite the 30 is equal to

sin(30°) = x / hypotenuse = x / 6

1 / 2 = x / 6

x = 3 is one side of the triangle

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#125 2010-05-24 00:05:02

misheeru
Member
Registered: 2010-02-18
Posts: 4,594

Re: Area problems Please Help!!

okay

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