Beau Peep Notice Board
Beau Peep Notice Board => Outpourings => Topic started by: Mince on March 05, 2007, 11:21:55 PM
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Work out the area of an equilateral triangle of sides 26.
I have a twelve-year-old who can do this.
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26 what?
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Potatoes. I think he's showing off again. ::)
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26 centimetres or 26 metres or 26 yards. The units are irrelevant.
I'm not showing off: she can do it, but I never said I could. I mean, okay, I can, but I didn't actually say I could.
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Er...338, I think. Surely every 12-year-old should be able to do that, or am I missing summat? Like a brain?
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Is 338 rounded off?
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Er...no - it's just wrong.
BUT....I realise my mistake, and I shall be back.
Apologies to all 12-year-olds - it's not quite as simple as I thought, bleary-eyed, over my morning coffee. In my defence, it's been over 30 years since I last sat in a maths class.
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Okay, the most accurate answer I can come up with is 292.71658647914026260613843171449 square units, but 292.5 would be fair.
There is a formula you can use, but basically you're working backwards from Pythagoras Theory, establishing the height of the equilateral triangle by taking the square of one of the sides (26x26) and subtracting the square of half of one of the other sides (13x13), and calculating the square root of the answer to give you the 'height' (i.e. the length of the perpendicular from the base of the triangle to its apex, which evenly bisects the triangle). Once established, you then simply multiply that height by half the base to get the total area of the equilateral triangle. The formula is [where s = the length of one side] Area = (s squared x the square root of 3) divided by 4.
Don't know how I missed it this morning, but once again, I apologise if I may have mislead you all, and good work to your 12-year-old.
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(http://www.nigelsutherland.co.uk/pictures/equation.jpg)
I think the answer's 27 cuttlefish.
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LOL!
Well done, Tarquin. We're quite the mathematician.
Peepmaster, what on Earth is that? Are you still failing basic algebra?
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Tarquin, try this one:
Four circles perfectly fit into one square. The shaded area is 16 (units squared). What is the area of the square?
(http://img.photobucket.com/albums/v67/BritTeacher/Beau%20Peep/FourCircles.jpg)
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And here is one more. Two cars are approaching each other head-on. One is travelling at a constant speed of 30mph and the other is travelling at a constant speed of 40mph. They begin 350 miles apart. A fly, sitting on the bumper of the first car at the beginning, flies at 60mph to the other car, and then turns round and flies back, and then continues to repeat flying back and forth between the cars until the cars crash and squash the fly. How far does the fly travel before it is squashed?
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Thankfully I have work to do now, but the answer to the first one is 16 plus [4 times (pi x circle radius squared)] units squared.
Regrettably, I haven't had time to apply any thinking to the second one, but I do know the last thing to go through the fly's head upon impact...
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Thankfully I have work to do now, but the answer to the first one is 16 plus [4 times (pi x circle radius squared)] units squared.
Hmm - I think it's 32 units, with each unit being of similar size.
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Thankfully I have work to do now, but the answer to the first one is 16 plus [4 times (pi x circle radius squared)] units squared.
There's just one problem. You don't know the radius.
The second problem is really easy.
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but I do know the last thing to go through the fly's head upon impact...
sniff of recognition
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Thankfully I have work to do now, but the answer to the first one is 16 plus [4 times (pi x circle radius squared)] units squared.
There's just one problem. You don't know the radius.
You asked what the area of the square is. Are you saying my answer is incorrect? Picky, picky, picky!
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Now is each side 26 potatoes, or is the sum of the three sides 26 potatoes?
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Now is each side 26 potatoes, or is the sum of the three sides 26 potatoes?
Sum ov the 3 sides is, sum aint.
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300 miles.
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Yes, well done, Fyodor.
The cars are approaching at a combined speed of 70mph and therefore will cover the 350 miles in 5 hours. In that 5 hours, the fly travels constantly at 60mph (in either direction) and therefore travels 300miles.
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That's more than five words
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300 miles isn't longer than five words - different units.
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three hundred miles is two syllables longer than five words.
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Malc, you're still using the old system: we've gone metric now.
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Malc, you're still using the old system: we've gone metric now.
No, you're on an old system too, Mince. That should read "I've gone mental now", (referring, of course, to you!
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Shut your bracket, Peepmaster.
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What shaded area?
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Don't worry about that, Fyodor - I already gave him the answer.
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Four circles perfectly fit into one square. The shaded area is 16 (units squared). What is the area of the square?
(http://img.photobucket.com/albums/v67/BritTeacher/Beau%20Peep/FourCircles.jpg)
ANSWER
We don't know the radius of the circles, so we just call it r.
The WIDTH OF THE SQUARE (and height) is four times the radius of the circles, which is 4r.
AREA OF SQUARE = base ? height = 4r ? 4r = 16r?
AREA OF EACH CIRCLE = PI ? r?
AREA OF SQUARE - AREA OF FOUR CIRCLES = SHADED AREA
16r? - PI ? r? = 16
This is where it gets difficult. We factorise for r?.
r?(16 - PI) = 16
Then we divide.
r? = 16 ? (16 - PI)
r? = 1.244
FINALLY
AREA OF SQUARE = 16r? = 16 ? 1.244 = 19.91
I have a twelve-year-old student who can do this.
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Yeah? Well can he do THIS?
drops trousers to reveal penis so long it is tied in a knot
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Unlikely . . . it's a she.
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Unlikely . . . it's a she.
It might be a friend's trousers.
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I'm glad the students currently sitting around my table doing free maths lessons don't know why I am laughing so much.
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Yeah? Well can he do THIS?
drops trousers to reveal penis so long it is tied in a knot
Would that be an Angler's Loop (http://www.tollesburysc.co.uk/Knots/Anglers_loop.htm) or a Sheepshank (http://www.tollesburysc.co.uk/Knots/Sheepshank.htm), Malc? Or are we talking Granny?
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I'm glad the students currently sitting around my table doing free maths lessons don't know why I am laughing so much.
You're watching students doing free maths lessons on a Saturday afternoon? Is this some kind of sado-masochism society?
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There is a sadistic side to it. They have to do three hours extra every weekend until they pass my maths test.
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Two of them just failed the test, so ve vill set zem more vork next veek.
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0800 1111
Your students may find the above useful.
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Bloody Childline! These kids need to be beaten, I tell ya, beaten!
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Free maths lessons? Wow, I bet they went like hot cakes.
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They are hard to shift at times.