Pythagorus Theory

[Bright_Spark]

This is probably one for the hardened enthusiast....

was flicking through a mates set of notes for his HNC and there was something written about pythagorus - an 'easy' method of tapping it all into your calculator to find an answer....

along the lines of 4 or 5 buttons......it involved squares and square routes etc...sorry its vaige...just wondered if anyone else knew about this 'easy' method and if they could explain it a bit to me.

i understand pythagorus theory and trig and i know how to work everything out....but not to this 'easy' method as its supposed to be.

dint have time to read everything in detail as i was browsing through it between doing things at work.

anyone throw any light onto this for me?
__________________________
Lynda, moderator

Moved, not an electrical question, and others may be able to help

 

[Spark123]

"The square of the hypotenuse is equal to the sum of the squares on the other two sides"
Hence "sqroot (o²+a²) = hyp"
or enter into calculator as "(o²+a²)sqroot = hyp

 

[RMS]

Pythagoros's theorm is basic maths to be honest. Finding a side of a right angle triangle when you know two sides. This is easily solved using a calculator.

i.e Square the two shorter sides and add them together. Then square root the answer to find the longest side. Re- arrange the formula to find any of the other sides.

As long as you know the square/square root buttons on your calculator then its simple.

 

[ricicle]

And Trig applies to the True, Apparent and Reactive power relationship as I'm sure you're aware

 

[Bright_Spark]

Pythagoros's theorm is basic maths to be honest. Finding a side of a right angle triangle when you know two sides. This is easily solved using a calculator.

i.e Square the two shorter sides and add them together. Then square root the answer to find the longest side. Re- arrange the formula to find any of the other sides.

As long as you know the square/square root buttons on your calculator then its simple.

i know its basic maths, but basic maths at HNC level might not be that basic...if it was, why do a GCSE in maths? just jump straight to HNC and get a higher qualification. i was just wondering if anyone could throw light onto this 'alternative' way of comming to the answer...

anyway, several of you have given me info on it which im grateful for!!!

many thanks to all.

 

[RMS]

If your considering taking on a HNC and don't feel all that confident with the maths then it would be advisable to take up the ONC first.

 

[noseall]

i tell people the 3,4,5 method.

if side A is 3 units, adjacent side B is 4 units then side C (hypotenuse) is 5 units. easy to remember.

3sq = 9
4sq = + 16
----
= 25

sq root of 25= 5.

 

[noseall]

i think my sums presentation needs a little work.

 

[BoxBasher]

Just to be a pedantic little git...

Its actually Pythagora's Theorem.

Although I've always found the easiest way to find out the lenght of something is using a tape measure, beats Pythag/Trig anyday.

 

[markie]

 

[noseall]

by using pythag you can check to see if a building is square.

 

[markie]

http://jwilson.coe.uga.edu/emt669/Student.Folders/Morris.Stephanie/EMT.669/Essay.1/Pythagorean.html

 

[nelsy]

Talking of sums and calculators - do you remember BODMAS from maths lessons

B work out any brackets first
O other operations - never really understood or used this one
D divide
M multiply this is equal to dividing
A add
S subtract this is equal to adding

This order is really important in any mathematics (like in English the rule is always read a page from left to right - top to bottom)

Try this out 2 + 3 x 4.

...

...

...

...

...

...

...

Many will say the answer is 20

2+3=5 then x4 =20

but mathematically this is the wrong answer.



but using BODMAS 2 + 3 x 4 = 14 this is the correct answer


3x4 = 12 (this is more important mathematically, therefore it should happen before adding anything on).

then add the 2

2 + 12 =14 the answer

Try this out on an ordinary calculator and the answer will be 20 as BODMAS isn't built into it's memory.
So you press 2 + 3 and it works it out to be 5, then x 4 = 20

But if you use a scientific calculator (for GCSE and higher) BODMAS is already built in, so

press 2 + 3 and the calculator is waiting to see if you press anything of a higher mathematical importance from BODM. Directly you press the x button, it stores the first number 2 and multiplies the 3 and 4 = 12 first - then it automatically adds the 2 to give the correct answer of 14.

Aint mafs grate

 

[BoxBasher]

by using pythag you can check to see if a building is square.

I remember using trig to calculate the height of a tall tree for my mate. He'd been asked to cut it down (being quite handy with a chainsaw) by his future "in-laws". I offered to calculate the height of the tree, and because he had supreme confidence in my ability to crunch numbers he took my answer as gospel and proceeded to hack away at the tree. He was that confident that he even bet his good lady's old man £20 it would miss the greenhouse and the fence.

I paid him back the £20, best money I'd spent in a long time. Well worth it for the look on his face as I told him I was lying about the height, just as the tree started going.

Edited to make more sense.

 

[AndersonC]

i tell people the 3,4,5 method.

if side A is 3 units, adjacent side B is 4 units then side C (hypotenuse) is 5 units. easy to remember.

3sq = 9
4sq = + 16
----
= 25

sq root of 25= 5.

Also 5, 12, 13.

5sq = 25
12sq = 144

Sum these = 169

Sq root of 169 = 13.

So if you have two perpendicular sides of the triangle measuring 12 and 5 inches the hypotenuse is 13 inches.