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20 replies

annie987 · 27/01/2020 22:16

We keep getting 12 but it’s not right. Very frustrated as I’m usually quite good at maths!

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OP posts:
meredithgrey1 · 27/01/2020 22:17

13?

Savoretti · 27/01/2020 22:18

It’s 13

Cantthinkofanythingrightnow · 27/01/2020 22:19

A=13

Terrytt · 27/01/2020 22:19

If a was 12 then a squared minus c squared would be zero
a squared = bsquared + c squared
a = square root of the sum of b squared and c squared.

Obsidian77 · 27/01/2020 22:19

13?

annie987 · 27/01/2020 22:20

Thank you. Don’t this the 3 glasses of rose have helped matters!!

OP posts:
Savoretti · 27/01/2020 22:20

12 ^2 is 144
You know the answer needs to be 25 as square root of 25 is 5 (b)
So 144 + 25 =169
That is 13 ^2

AliMonkey · 27/01/2020 22:20

so to get to 13, you square both sides, giving:
b2 = a2-c^2
so a2=b2+c^2=25+144=169
therefore b=13

Muddlingalongalone · 27/01/2020 22:21

13

B=5 & square root of 25 =5 therefore a2-144 = 25
144+25=169
Square root of 169 = 13

Cantthinkofanythingrightnow · 27/01/2020 22:21

Here you go.

To ask for help with this Maths question
andyindurham · 27/01/2020 22:21

If b=5, then the difference between a2 and c2 must be 25 (5=square root of 25). c2 (12*12) = 144. 144+25=169. Square root of 169=13.

Thus a=13

And to check:
1313=169
12
12=144
169-144=25
square root of 25=5, which we already know is the value of b.

Terrytt · 27/01/2020 22:22

method -

  1. suare both sides gives b squared = a squared - c squared
  2. add c squared to both sides gives b squared + c squared = a squared
  3. square root both sides gives square root of the sum of b squared and c squared = a
DropZoneOne · 27/01/2020 22:23

It's 13
If b is 5, then it's the square root of 25
So a squared less c squared = 25
c is 12, so c squared is 144
So a squared must be 144+25=169
making c=13

Unshriven · 27/01/2020 22:23

Yes, I get 13 too.

The square root of 169.

annie987 · 27/01/2020 22:24

So obvious now! Thanks

OP posts:
dementedpixie · 27/01/2020 22:24

I get 13 too.
Square both sides so b2 = a2- c2
a2= b2 + c2
a2 = 25 + 144
a2 = 169
a = 13

(Sorry could do small 2s)

ItsGoingTibiaK · 27/01/2020 22:25

It’s 13.

To ask for help with this Maths question
Ginfordinner · 27/01/2020 22:25

I got 13 as well.
I still have it!

DadDadDad · 27/01/2020 22:47

You all missed one: you could also have a = -13.

Livingthedream12345 · 27/01/2020 23:00

Yep. 13.
It's a pythagorean triple. 5,12 and 13.

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