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#1 2015-10-09 02:27:52
- mathster
- Member
- Registered: 2015-10-09
- Posts: 15
Hard area problem.
What is the area in square inches of the pentagon shown?
Could someone please tell me the answer? Solution preferred, but optional.
Thanks in advance.
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#2 2015-10-09 03:09:45
- David
- Member
- From: Bumpkinland
- Registered: 2014-04-23
- Posts: 3,164
Re: Hard area problem.
Some pythagorean theorem and heron's formula would do the trick. Give me some time to revise my latex...
His dominion is an everlasting dominion, Which shall not pass away, And His kingdom the one Which shall not be destroyed.
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#3 2015-10-09 03:33:13
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Hard area problem.
Hi;
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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#4 2015-10-09 03:54:58
- David
- Member
- From: Bumpkinland
- Registered: 2014-04-23
- Posts: 3,164
Re: Hard area problem.
Hi;
Here's how it work. Let me know if you need further assistance.
Last edited by David (2015-10-09 03:59:56)
His dominion is an everlasting dominion, Which shall not pass away, And His kingdom the one Which shall not be destroyed.
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#5 2015-10-09 04:10:34
- phrontister
- Real Member
- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 4,877
Re: Hard area problem.
Hi mathster;
I've added lines CD and DF to the image, which I hope will help give you a better idea of how to go about tackling this.
DCF is a right-angled triangle - as is its congruent (equal sides) neighbour DEF - and so the area formula for right-angled triangles applies to those two triangles. Then add the area of rectangle ABCD to give you the area of pentagon ABFED.
Last edited by phrontister (2017-02-26 23:40:21)
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#6 2015-10-09 04:15:42
- David
- Member
- From: Bumpkinland
- Registered: 2014-04-23
- Posts: 3,164
Re: Hard area problem.
They do look like right triangles! Lol...
His dominion is an everlasting dominion, Which shall not pass away, And His kingdom the one Which shall not be destroyed.
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#7 2015-10-09 04:45:52
- mathster
- Member
- Registered: 2015-10-09
- Posts: 15
Re: Hard area problem.
Wow, drawing BF never occurred to me. Thanks a lot everyone!
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