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#1 2010-04-30 09:55:44

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

Area problems Please Help!!

I need to figure out how to find the area of a regular hexigon with the given measurement.

The only info they give you is: 2√3 apothem

please help idk what to do!


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#2 2010-04-30 12:50:43

ZHero
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Registered: 2008-06-08
Posts: 1,889

Re: Area problems Please Help!!

Hi misheeru!

A Circle can be Inscribed in a Regular Hexagon and the Radius of such an Inscribed Circle is called an Apothem!

If u join all the Vertices of the Hexagon to the Centre of the Circle then 6 Equilateral Triangles will be formed, each with an Altitude equal to the Radius or the Apothem!

So, simply find the Area of 1 Equilateral Triangle using

and multiply it by 6 to find the Area of the Hexagon!

Last edited by ZHero (2010-04-30 15:06:01)


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#3 2010-04-30 13:19:04

soroban
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Registered: 2007-03-09
Posts: 452

Re: Area problems Please Help!!

.

          * - - - *
         / \     / \
        /   \   /   \
       /     \ /     \
      * - - - * - - - *
       \     /:\     /  :   _
        \   / : \   /   : 2√3
         \ /  :  \ /    :
          * - - - *     -
              4


.

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#4 2010-04-30 15:08:41

ZHero
Real Member
Registered: 2008-06-08
Posts: 1,889

Re: Area problems Please Help!!

Hi soroban!

I made a mistake in defining the Apothem and hence the Area of the Eq. Tri.
I've corrected it!!


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#5 2010-05-03 04:54:48

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

Re: Area problems Please Help!!

Okay,  I see how you got that. I'm really having a hard time with these still, though. But I'll take a crack at a few more and let you know if I need any more help. thanks so much guys!!! kiss

Last edited by misheeru (2010-05-03 04:55:13)


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#6 2010-05-03 05:19:37

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

Re: Area problems Please Help!!

"I'' ll try some on my own" wow that was short lived. Thank you every one for your help, unfortunaly I need some more!

*Find the area of an equilateral triangle (regular 3-gon) with the given measurement.

Given: 6-inch side

Please help!!

Last edited by misheeru (2010-05-03 05:19:57)


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#7 2010-05-03 05:43:57

ZHero
Real Member
Registered: 2008-06-08
Posts: 1,889

Re: Area problems Please Help!!

faint

plz look for the formula for Area in the other reply above...


here, ur Side is given!  eek

smile  smile   big_smile   tongue


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#8 2010-05-03 13:16:01

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

Re: Area problems Please Help!!

Hi misheeru;


Or try this:

Start with equilateral triangle ABC. Drop the perpendicular bisector BD to AC. It is easy to prove this can be done. Now AD = DC = 3. Just use pythagoras theorem to get  the height BD.

Call h = BD, then find h.

h^2 + 3^2 + 6^2

a^2 = 27

h = √27 = 3√3

Now just use A = ( b * h ) / 2

A = ( 6 * 3√3 ) / 2  = 9 √3


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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#9 2010-05-05 07:16:01

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

Re: Area problems Please Help!!

Okay so with triangles, I I was told to use : area (A) = 1/2 bh

So one of my problems is this: In a triangle the base is 4 inches and the height is 6 inches. Find the area.


I'd start with: A= 1/2bh

                    A= 1/2 (4*6)

                    A= 1/2 (24)

                    A= 12

So it would be: A= 12in² ? Is that right?


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#10 2010-05-05 07:27:45

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

Re: Area problems Please Help!!

Hi misheeru;

Correct! Formulas are great aren't they? You just plug in and whamo!


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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#11 2010-05-05 09:07:35

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

Re: Area problems Please Help!!

LOL, I suppose. I just wish they were easier for me to figure out... oh well, I guess, like everything else, they require practice. tongue


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#12 2010-05-06 19:14:00

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

Re: Area problems Please Help!!

Okay so my lessons have moved once again. Right now I'm in "Circles: Area Of Sectors".

I get a little bit of this, but not much. I found this video this lady made on youtube and it really helped me, but I get lost right after about 5:50 in it. yikes

Her circle has a radius of 7cm and an angle of 120 degrees.

I used a problem from my work to follow her video. The circle I used had a radius of 8 inches and an angle of 40 degrees.

I worked with her up until the final equation wich was:

1/3 * 22/7 *7 * 7  (mine was  1/9 * 22/7 * 8 * 8)

at 5:50 the teacher announces that her answer is 51.3 cm. Can some one please help me, I can't seem to figure out how she came to that answer. That way I can figure out mine, and hopefully get this whole concept down. Thanks! big_smile

Heres the youtube link to the vid I used:  http://www.youtube.com/watch?v=brErtLcvXvo


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#13 2010-05-06 19:18:25

ZHero
Real Member
Registered: 2008-06-08
Posts: 1,889

Re: Area problems Please Help!!

hi

she is right and her answer is correct.
your's is also fine!!!

i guess somebody might explain to you in detail bout the Concept.
its got something to do with fractions.........
smile


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#14 2010-05-06 20:44:51

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

Re: Area problems Please Help!!

Hi misheeru;

Where are you having a problem? Can you leave a link of the you tube vid?


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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#15 2010-05-07 04:45:48

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

Re: Area problems Please Help!!

Oh shoot! I totally posted the wrong link! I should've checked that before I went to sleep. I'm sorry. yikes

Okay, my bad I think its this one: http://www.youtube.com/watch?v=brErtLcvXvo

I just don't know how she got her answer from the final equation at about 5:50 or so. Like, how do I explain this, I don't know how to work the equation and come to the answer 51.3. hmm


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#16 2010-05-07 04:51:20

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

Re: Area problems Please Help!!

Hi misheeru;

Do you understand her method of getting the area of a circle?


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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#17 2010-05-07 05:09:13

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

Re: Area problems Please Help!!

Yeah, I think so. Here, one of the problems on my homework is an area of a circle problem:

Find the area of the circle with the given radius or diameter. Use π= 3.14. (my school prefers that we use the 3.14 instead of the 22/7)

A = πr^2   r =6

A= 3.14 * 6 * 6

A = 113.04

Hows that?


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#18 2010-05-07 05:13:44

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

Re: Area problems Please Help!!

That is correct. Now supposing I wanted the area of the sector formed by an angle of 60°


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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#19 2010-05-07 05:24:23

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

Re: Area problems Please Help!!

Don't you have to know the radius, too?


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#20 2010-05-07 05:25:51

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

Re: Area problems Please Help!!

Same radius as she is using in the video, r = 7


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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#21 2010-05-07 05:33:50

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

Re: Area problems Please Help!!

okay. So then we are left with an angle of 60° and a radius of 7.

Then we have 60/360 * πr^2 .

so thats.... 1/6 * 3.14 * 7 * 7?


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#22 2010-05-07 05:35:52

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

Re: Area problems Please Help!!

That's right. So what is it that you do not understand? Looks like you understand it fine, Just remember to include your units at the end.


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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#23 2010-05-07 05:42:19

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

Re: Area problems Please Help!!

Um... okay. thanks then! big_smile


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#24 2010-05-07 05:45:16

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

Re: Area problems Please Help!!

Glad to help. Did you remember that this is an area problem? There is some unit of measure squared on the end. In this case cm²


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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#25 2010-05-07 05:50:58

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

Re: Area problems Please Help!!

Okay so if I'm just supposed to multiply them together, would it be:

1/6 * 3.14 * 7 * 7 = 25.643

A= 25.643 cm²??


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