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## #26 2009-01-07 19:49:13

jaypee
Guest

### Re: finding the missing side of a triangle

...can you help me in my research about Pythagorean triples..given only a side of right triangle..what is the easiest method to derive the other two sides?
secondly, if the given side is the hypotenuse,what is the measure of the other two legs?

## #27 2009-01-07 20:18:00

ganesh
Moderator
Registered: 2005-06-28
Posts: 22,065

### Re: finding the missing side of a triangle

Pythagorean triples are of the form.

In my opinion, given only one side of a right-angled triangle, it is not possible to find the other two sides.
Consider this counter-example.
(5, 12, 13) are the sides of a right angled triangle.
(9, 12, 15) are also the sides of a right angled triangle.
If you are given only one side, namely, 12, how would you say which are the other two sides?

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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## #28 2009-01-08 14:21:37

darkestrocker
Guest

### Re: finding the missing side of a triangle

30-60-90

the sides are always

side across from 30- 1
side across from 60- square root of 3
side across from 90- 2

## #29 2009-03-25 01:34:22

loolabell
Guest

### Re: finding the missing side of a triangle

Is there some one on that can help me with this problem
I =
I   =
I      =
I        =     15
I           =
X+6       I             =
I               =
I                 =
I____________
X+3

I need to solve for x and the perimeter of the triangle:)

## #30 2009-03-25 02:43:03

mathsyperson
Moderator
Registered: 2005-06-22
Posts: 4,900

### Re: finding the missing side of a triangle

The three sides make up a right-angled triangle, so you want to find x such that their lengths are a Pythagorean triple.

You might be able to spot a triple hiding in there just by looking.
Otherwise, square everything and solve the equation:

(x+3)² + (x+6)² = 15².

This will have two answers, but only the positive one makes sense in this context so that's the one you use.
After you know all the side lengths, finding the perimeter is simple.

Why did the vector cross the road?
It wanted to be normal.

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## #31 2009-03-26 16:11:09

smiyc86
Member
Registered: 2009-03-19
Posts: 78

### Re: finding the missing side of a triangle

mathsyperson wrote:

On a 30-60-90 triangle, the longest side is always twice as big as the shortest side.
That fact, along with Pythagoras and the side length you know, should let you find out everything about the triangle.

to add to that ... the sides of the triangle will be in the ratio (side opp to 30 deg):(side opp to 60 deg):side opp to 90 deg) = 1:√3:2 ....

I love Maths and Music ... dunno which more

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## #32 2009-03-30 10:46:11

person...
Guest

### Re: finding the missing side of a triangle

THIS IS MAKING ME EVEN MORE CONFUSED!!! YOU HAVE TO EXPLAIN IN NORMAL WORDS BEFORE YOU USE THE MATH TERMS OR NO ONE WILL UNDERSTAND!!! DON'T HELP IF YOU CANT HELP IN ENGLISH!!!GRRRR

## #33 2009-03-30 17:25:44

smiyc86
Member
Registered: 2009-03-19
Posts: 78

### Re: finding the missing side of a triangle

opp = opposite
deg = degrees ....

now does that make me clear ?? it was english dude ... just few short forms which i thought any person with a min IQ will understand

ohh btw ,

min = minimum
IQ = Intelligence Quotient

:rofl

I love Maths and Music ... dunno which more

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## #34 2009-04-23 08:55:35

daughterearth
Guest

### Re: finding the missing side of a triangle

THANKZ YALL!!!!!! u guys helped ma a lot

## #35 2009-06-08 11:23:34

hollyy j
Guest

### Re: finding the missing side of a triangle

im in 8th grade algbra 1 and what you do is take a squared and add it by b squared these are the sides of the triangle it really dosnt matter which order they go in then you square both number s and add them together to get c squared.. then you take that awnser and get the square root of that and there is the awnser for the missing length. (:

## #36 2009-12-12 16:04:00

28
Guest

### Re: finding the missing side of a triangle

cool dude thanks a lot.

## #37 2010-01-05 20:16:57

ace b
Guest

### Re: finding the missing side of a triangle

On a 32,55 triangle, what is x in this equation]

michelle259
Guest

:

## #39 2010-01-17 06:06:51

trig >:P
Guest

### Re: finding the missing side of a triangle

okay. so my final is in 3 days and im screwed. im looking at my final review packet and their are a few things that are really confusing me. i just don't get it but i catch on easy.. sometimes. if it has meaning.
is someone willing to help a lost cause... heres the question if you are.

solve triangle ABC if a=8    b=5    c=11
B
/  \
/      \
8 /           \  11
/              \
/_________\
A          5        C

***HELP!!!***

## #40 2010-01-17 06:34:21

bobbym
From: Bumpkinland
Registered: 2009-04-12
Posts: 107,776

### Re: finding the missing side of a triangle

Hi trig >:P;

What are you looking for?

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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## #41 2010-01-20 18:34:38

craig b
Guest

### Re: finding the missing side of a triangle

A right triangle has a leg measuring 52 m and a hypotenuse measuring 63 m. Find the length of the other leg.

## #42 2010-01-20 18:36:58

craig b
Guest

### Re: finding the missing side of a triangle

craig b wrote:

A right triangle has a leg measuring 52 m and a hypotenuse measuring 63 m. Find the length of the other leg.

Hey man can i get some help

## #43 2010-01-20 21:03:14

bobbym
From: Bumpkinland
Registered: 2009-04-12
Posts: 107,776

### Re: finding the missing side of a triangle

Hi craig b;

You use the pythagorean theorem. Call the missing leg x.

52^2 + x^2 = 63^2

Now solve for x:

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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## #44 2010-01-22 13:05:23

Eos15
Guest

### Re: finding the missing side of a triangle

This is for the people who dont understand the pythagorean theorem. How to calculate the missing side of a right triangle. Here is an example....         A = bottom of triangle   B = Side of triangle   C = missing side........  A = 24   B = 10  now you just sqaure both numbers.... on your calculater if you have one is an X with an exponent 2 above it and that symbol means square.... square both numbers 24 squared = 576    10 squared = 100   both added = 676...... now 676 = 26 squared. If you don't get it now your hopeless.  JK

## #45 2010-01-22 14:08:34

bobbym
From: Bumpkinland
Registered: 2009-04-12
Posts: 107,776

### Re: finding the missing side of a triangle

Hi;

If you don't get it now your hopeless.

Not exactly, it just means you need more examples and some patience.

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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## #46 2010-05-17 12:29:01

Lucy 567
Guest

### Re: finding the missing side of a triangle

LuisRodg wrote:
Sunnayyy wrote:

i need help figuring out how to find the missing side of a right triangle with legs: a= 12, and b=9....?

So by following the formula given before:

Where:

a and b are the sides and c is the hypotenuse.

So you have sides a=12 and b=9.

Thanks! That helped SO much!!!

## #47 2010-06-02 09:40:23

loganlambe1155
Member
Registered: 2010-05-28
Posts: 10

### Re: finding the missing side of a triangle

its easy dude use the pythagoreon theorem its defined as "the sqaure of hypotenus of a triangle is equal to the sum of sqaure of base and square of perpendicular".

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## #48 2010-06-03 02:25:07

Member
Registered: 2010-06-02
Posts: 4

### Re: finding the missing side of a triangle

Well it seems that a lot of people don't seem to understand which side is which and hence getting confused.  when i teach my students, i enphasize on labelling the sides properly before attempting a question.  So whenever you have a right angle triangle and you are missing a side, say to yourself that you are going to use pythagoras.

Pythagoras theorem is a^2+b^2=c^2

get into the habit of labeling the shortest side a, the longest side c and the medium side b.  Once you have labelled them, you should be able to see which side you need to work out.  depending on that use the following formulae

if you are missing a then use:

a^2=c^2-b^2

if you are missing b then use:

b^2=c^2-a^2

and if you are missing c then use

c^2 = a^+b^2

now its just a matter of picking the right formula and changing the letters with the corresponding numbers and squaring them appropriately.   Hope that helps

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## #49 2010-10-12 05:16:10

Kelly Smith
Guest

### Re: finding the missing side of a triangle

i still don't get it.

## #50 2010-10-12 07:01:25

bobbym
From: Bumpkinland
Registered: 2009-04-12
Posts: 107,776

Hi Kelly;