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# Help me help him Geometry/Algebra Which one of you moms is good at Algebra?

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I'm trying to fing the pereimter of an irregular polygon with missing sides. It seems easy but then I get confused. WE could wait until our tutoing session bu the problem is pissing me off. LOL

So???? Who can help? It's one were several sides are missing and I know there must be an easy formula.

Some people recognize the light but they can't handle the glare.

by on Feb. 4, 2013 at 1:10 PM
Replies (11-20):
by Platinum Member on Feb. 5, 2013 at 6:46 AM
Quoting SunFlower700:

I first just calculated the 6 for the tiny vertical line. The other short vertical line was also 6 so that made 12 so 20-12=8!to give me that longer missing vertical measurement.

The line opposite 18 had to be 18-6.

I just felt like I was thinking too hard. I do not understand where you got 20 +20 though. Where did you get that? Did you just quickly combine the 8+6+6?

Some people recognize the light but they can't handle the glare.

by Platinum Member on Feb. 5, 2013 at 6:48 AM
Quoting MsNeene:

126. The four missing sides are 6,6,8 and 12.

Oh that's how you gon' do it? Lol

Explain that girl!

Some people recognize the light but they can't handle the glare.

by on Feb. 5, 2013 at 12:58 PM
1 mom liked this
I kind of did it the same way you explained LOL. It was a bunch if steps because there were so many missing parts so I couldn't just make a quick formula. Guess the people who wrote that problem wanted it to be hard because I was like damn that's a lot of missing sides LOL!! I think if they would have told you what the total perimeter actually was then asked you to fill in the blank you could have made a little formula but they didnt even give you the perimeter. So there might have been an easier way but I couldn't figure it out without the perimeter I had to do it the long way :-( lol damn math is always asking crazy questions
by Platinum Member on Feb. 5, 2013 at 1:21 PM
Here is one that's worse But I'm having a hard time with it.

Quoting MsNeene:

I kind of did it the same way you explained LOL. It was a bunch if steps because there were so many missing parts so I couldn't just make a quick formula. Guess the people who wrote that problem wanted it to be hard because I was like damn that's a lot of missing sides LOL!! I think if they would have told you what the total perimeter actually was then asked you to fill in the blank you could have made a little formula but they didnt even give you the perimeter. So there might have been an easier way but I couldn't figure it out without the perimeter I had to do it the long way :-( lol damn math is always asking crazy questions
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by Platinum Member on Feb. 5, 2013 at 1:22 PM

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by on Feb. 5, 2013 at 3:14 PM
Quoting Dana267:

Ok that one is a little better lol. That one is 140 meters for the perimeter. The two sides the show are 20 and 50 plus the other sides on the top all add up to 50 and all the sides on the sides add up to 20 so it p = 20+50+20+50 and it solves for 140.

Kind of hard to explain but if you look at it and draw a dotted line for all the pieces and extend them they would all line up and be the same length as the sides the showed you only difference is they had them at different levels so make it look hard. So you can make the line imaginary to see if it would be the same size as the other line but that will only work to find tr perimeter it wouldn't work as well for finding the area though.
by Platinum Member on Feb. 5, 2013 at 3:40 PM
Awesome Explanation!!!!!

This one is easier. Duh me.

Quoting MsNeene:

Quoting Dana267:

Ok that one is a little better lol. That one is 140 meters for the perimeter. The two sides the show are 20 and 50 plus the other sides on the top all add up to 50 and all the sides on the sides add up to 20 so it p = 20+50+20+50 and it solves for 140.

Kind of hard to explain but if you look at it and draw a dotted line for all the pieces and extend them they would all line up and be the same length as the sides the showed you only difference is they had them at different levels so make it look hard. So you can make the line imaginary to see if it would be the same size as the other line but that will only work to find tr perimeter it wouldn't work as well for finding the area though.
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by on Feb. 5, 2013 at 4:45 PM
1 mom liked this

I just came in to be nosey....I suck at math lol

by Gold Member on Feb. 5, 2013 at 6:10 PM

I interpreted the question as asking what the "perimetre" was but not the sizes of where the question marks are, and the clue "all the angles are right angles".  Since the left side is 20 metres, and all the angles are right angles, the right side would also have to be 20 metres.  But you could take it further to find the measurements of where the question marks are by

12 divided by 2 = 6 (the two smaller sides are 6 metres each).
The 12 meters from 25-13=12  (the horizontal section just above the 25m)

20 metres minus 12 metres = 8 metres the size of top bigger section with the question mark.

Quoting Dana267:

Quoting SunFlower700:

I first just calculated the 6 for the tiny vertical line. The other short vertical line was also 6 so that made 12 so 20-12=8!to give me that longer missing vertical measurement.

The line opposite 18 had to be 18-6.

I just felt like I was thinking too hard. I do not understand where you got 20 +20 though. Where did you get that? Did you just quickly combine the 8+6+6?

by Gold Member on Feb. 5, 2013 at 6:19 PM

That's how I interpreted the math question and would have calculated it out the same as how you did.

Quoting MsNeene:

Quoting Dana267:

Ok that one is a little better lol. That one is 140 meters for the perimeter. The two sides the show are 20 and 50 plus the other sides on the top all add up to 50 and all the sides on the sides add up to 20 so it p = 20+50+20+50 and it solves for 140.

Kind of hard to explain but if you look at it and draw a dotted line for all the pieces and extend them they would all line up and be the same length as the sides the showed you only difference is they had them at different levels so make it look hard. So you can make the line imaginary to see if it would be the same size as the other line but that will only work to find tr perimeter it wouldn't work as well for finding the area though.