Omega Owners Forum
Chat Area => General Discussion Area => Topic started by: Darth Loo-knee on 30 September 2011, 20:35:07
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It seems to take ages to go over and over to get my head around the maths questions our Lilo has to do......
I don't even remember doing "What are the interior degrees of a Polygon with 22 sides!"
Does anyone else remember doing maths like that or is it just me? :-\
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It seems to take ages to go over and over to get my head around the maths questions our Lilo has to do......
I don't even remember doing "What are the interior degrees of a Polygon with 22 sides!"
Does anyone else remember doing maths like that or is it just me? :-\
How's this Daz?
http://www.mathsisfun.com/geometry/interior-angles-polygons.html
We did some of this kind of thing, but it was a very long time since I left school. There are far more useful things they could be teaching kids though eg banking & other everyday maths.
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Angles Any polygon, regular or irregular, self-intersecting or simple, has as many corners as it has sides. Each corner has several angles. The two most important ones are:
- Interior angle (http://en.wikipedia.org/wiki/Interior_angle) – The sum of the interior angles of a simple n-gon is (n − 2)π (http://en.wikipedia.org/wiki/Pi) radians (http://en.wikipedia.org/wiki/Radian) or (n − 2)180 degrees (http://en.wikipedia.org/wiki/Degree_(angle)). This is because any simple n-gon can be considered to be made up of (n − 2) triangles, each of which has an angle sum of π radians or 180 degrees. The measure of any interior angle of a convex regular n-gon is (http://upload.wikimedia.org/math/a/7/9/a79976e0885acc381bcc0b727e0b3e05.png) radians or (http://upload.wikimedia.org/math/f/f/5/ff5e038fe8d9886485f261156b73e531.png) degrees. The interior angles of regular star polygons (http://en.wikipedia.org/wiki/Star_polygon) were first studied by Poinsot, in the same paper in which he describes the four regular star polyhedra (http://en.wikipedia.org/wiki/Kepler-Poinsot_polyhedron).
- Exterior angle (http://en.wikipedia.org/wiki/Exterior_angle) – Imagine walking around a simple n-gon marked on the floor. The amount you "turn" at a corner is the exterior or external angle. Walking all the way round the polygon, you make one full turn (http://en.wikipedia.org/wiki/Turn_(geometry)), so the sum of the exterior angles must be 360°. Moving around an n-gon in general, the sum of the exterior angles (the total amount one rotates at the vertices) can be any integer multiple d of 360°, e.g. 720° for a pentagram (http://en.wikipedia.org/wiki/Pentagram) and 0° for an angular "eight", where d is the density or starriness of the polygon. See also orbit (dynamics) (http://en.wikipedia.org/wiki/Orbit_(dynamics)).
The exterior angle is the supplementary angle (http://en.wikipedia.org/wiki/Supplementary_angle) to the interior angle. From this the sum of the interior angles can be easily confirmed, even if some interior angles are more than 180°: going clockwise around, it means that one sometime turns left instead of right, which is counted as turning a negative amount. (Thus we consider something like the winding number (http://en.wikipedia.org/wiki/Winding_number) of the orientation of the sides, where at every vertex the contribution is between −½ and ½ winding.)
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and you remembered that from school Capt? I'm impressed! ;D ;D ;D
Billy Connolly sums it up some of the stuff we were taght at school quite well ;D ;D ;D
http://www.youtube.com/watch?v=JqZo07Ot-uA
;D ;D ;D
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I have problems helping, even with basic maths, it is the seemingly logical, to me, way they work them out now, even basic addition is done is a line..... ::) ::) :-[
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Easiest way that I remember is to "imagine" the polygon as a series of triangles by joining the corners to one point. You can make n-2 triangles (where n is the number of sides - imagine a square 4 sides join opposite corners makes 2 triangles.) Now it is a standard of geometry that the total of all the angles in a triangle is 180 degrees, so multiply by 180 and you have the total number of degrees. Now divide by the number of sides and you have the answer ...
((n-2)*180)/n for 22 sides that is ((22-2)*180)/22 = (20*180)/22 = 3600/180 = 163.6363
HTH
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Easiest way that I remember is to "imagine" the polygon as a series of triangles by joining the corners to one point. You can make n-2 triangles (where n is the number of sides - imagine a square 4 sides join opposite corners makes 2 triangles.) Now it is a standard of geometry that the total of all the angles in a triangle is 180 degrees, so multiply by 180 and you have the total number of degrees. Now divide by the number of sides and you have the answer ...
((n-2)*180)/n for 22 sides that is ((22-2)*180)/22 = (20*180)/22 = 3600/180 = 163.6363
HTH
you didn't read my link then Nige ::) ::) ::) ::) ;D ;) ;)
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Easiest way that I remember is to "imagine" the polygon as a series of triangles by joining the corners to one point. You can make n-2 triangles (where n is the number of sides - imagine a square 4 sides join opposite corners makes 2 triangles.) Now it is a standard of geometry that the total of all the angles in a triangle is 180 degrees, so multiply by 180 and you have the total number of degrees. Now divide by the number of sides and you have the answer ...
((n-2)*180)/n for 22 sides that is ((22-2)*180)/22 = (20*180)/22 = 3600/180 = 163.6363
HTH
you didn't read my link then Nige ::) ::) ::) ::) ;D ;) ;)
I rarely click u-tube links .. I find most of them pants .... :)
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I have problems helping, even with basic maths, it is the seemingly logical, to me, way they work them out now, even basic addition is done is a line..... ::) ::) :-[
Seems so much easier adding up, mulitiplying or subtracting with the numbers under each other. I showed our girls and the teacher told me at Parents evening when I mentioned it that children need to learn all different ways in maths, so i asked "Why did you not show them my way then?" the answer was, "We have not got around to that yet" yeah right, they never did it ........
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Nige i managed it ;D but the n=-2 or whatever totally had me confused :-[
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I use this one for my lads homework (when he brings it home >:()
http://www.purplemath.com/modules/index.htm
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Easiest way that I remember is to "imagine" the polygon as a series of triangles by joining the corners to one point. You can make n-2 triangles (where n is the number of sides - imagine a square 4 sides join opposite corners makes 2 triangles.) Now it is a standard of geometry that the total of all the angles in a triangle is 180 degrees, so multiply by 180 and you have the total number of degrees. Now divide by the number of sides and you have the answer ...
((n-2)*180)/n for 22 sides that is ((22-2)*180)/22 = (20*180)/22 = 3600/180 = 163.6363
HTH
you didn't read my link then Nige ::) ::) ::) ::) ;D ;) ;)
I rarely click u-tube links .. I find most of them pants .... :)
Not the YouTube link, the first one ie mathisfun ..... ;) ;)
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Easiest way that I remember is to "imagine" the polygon as a series of triangles by joining the corners to one point. You can make n-2 triangles (where n is the number of sides - imagine a square 4 sides join opposite corners makes 2 triangles.) Now it is a standard of geometry that the total of all the angles in a triangle is 180 degrees, so multiply by 180 and you have the total number of degrees. Now divide by the number of sides and you have the answer ...
((n-2)*180)/n for 22 sides that is ((22-2)*180)/22 = (20*180)/22 = 3600/180 = 163.6363
HTH
you didn't read my link then Nige ::) ::) ::) ::) ;D ;) ;)
I rarely click u-tube links .. I find most of them pants .... :)
Not the YouTube link, the first one ie mathisfun ..... ;) ;)
Sorry .. never spotted that one .. :( would have saved me brain and me typing fingers if I had.
At least I got the theory right !!
Least ways it proves the memory is still working ... been many a year since the OU Degree .. and even more since A-level days !!!
:)
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I had to go and ask our eldests teacher how they were teaching simple adding and subtracting. He came home talking about units and columns and moving things accross! Had it explained and it still didn't make sense, far too abstract....which is an issue considering our eldest is autistic! Shall be investing in some key stage 2 maths books I think. :-[
His homework seems to be for us to do not him too. He's 7 and had to research an indian village, then print out a photo, now its build an indian house! Don't mind helping him but its beyond him so end up doing it! >:(
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Easiest way that I remember is to "imagine" the polygon as a series of triangles by joining the corners to one point. You can make n-2 triangles (where n is the number of sides - imagine a square 4 sides join opposite corners makes 2 triangles.) Now it is a standard of geometry that the total of all the angles in a triangle is 180 degrees, so multiply by 180 and you have the total number of degrees. Now divide by the number of sides and you have the answer ...
((n-2)*180)/n for 22 sides that is ((22-2)*180)/22 = (20*180)/22 = 3600/180 = 163.6363
HTH
you didn't read my link then Nige ::) ::) ::) ::) ;D ;) ;)
I rarely click u-tube links .. I find most of them pants .... :)
Not the YouTube link, the first one ie mathisfun ..... ;) ;)
Sorry .. never spotted that one .. :( would have saved me brain and me typing fingers if I had.
At least I got the theory right !!
Least ways it proves the memory is still working ... been many a year since the OU Degree .. and even more since A-level days !!!
:)
Teachers Pet ;D ;D
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I had to go and ask our eldests teacher how they were teaching simple adding and subtracting. He came home talking about units and columns and moving things accross! Had it explained and it still didn't make sense, far too abstract....which is an issue considering our eldest is autistic! Shall be investing in some key stage 2 maths books I think. :-[
His homework seems to be for us to do not him too. He's 7 and had to research an indian village, then print out a photo, now its build an indian house! Don't mind helping him but its beyond him so end up doing it! >:(
The stuff Our eldest comes home with and has had to do at school is in my book stupid..
I know we are a multi cultured country but as far as I am concerned this is still a Christian Country. In RE they we doing different cultures which is fine, but went onto killing animals as different religions do it in different ways...... We know have a 15 year old daughter who since that day has become a Veggie...
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Maths - yes I have had to teach the children more efficient ways.
Primary kept on about number lines. I introduced them to numbers like
123
+456
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579
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I guess it depends how much math you have to use in daily life.... if like me, your work often involves significant amounts of math, with big scary piles of statistical math, geometry and calculus, (acoustics calculations , wave form analysis, fast fourier transforms, for audio DSP etc etc ... ) then GCSE homework , is really not an issue...
if on the other hand, your routine life experience only stretches you to work out the finances each month, and the darts score on a friday... then i would hazard a guess some of it will sound like a foreign language..... I can't think of even once that i've needed , for example, complex matrices and simultaneous equations OUTSIDE of work.... or the kids homework.