The Pythagorean Theorem, help with solving problems?

Question

anonymous · Answer

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anonymous · Answer

$$8^2+b^2=17^2$$ is a good first step

igreen · Answer

$a^2 + b^2 = c^2$

Where a and b are the two legs, and c is the hypotenuse.

Plug in what we know:

$a^2 + 8^2 = 17^2$

Now solve for 'a'.

anonymous · Answer

$$9^2$$ right?

igreen · Answer

Um..no..simplify $8^2$ and $17^2$.

anonymous · Answer

hmm no
do the arithmetic

anonymous · Answer

Well 8^2 + 17^2 = 353

igreen · Answer

No, we want to simplify the separately.

igreen · Answer

We're actually going to be doing:

$17^2 - 8^2$

anonymous · Answer

289 - 64 = 225

igreen · Answer

Yes, so we have:

$a^2 = 225$

Now find the square root off both sides.

igreen · Answer

*of

anonymous · Answer

Wait, you lost me again.. Sorry, not good at math at all.

igreen · Answer

Well, we want to get rid of the exponent of 2 on 'a', so we have to find the square root of both sides.

$a^2 = 225 \rightarrow \sqrt{a^2} = \sqrt{225}$

The square root cancels out the exponent, leaving us with just 'a'.

$a = \sqrt{225}$

anonymous · Answer

Well the square root of 225 is 15. So a=15?

anonymous · Answer

yes, this is a very famous right triangle 
$$8,15,17$$

anonymous · Answer

Okay, thank you guys for explaining it.

anonymous · Answer

now quite as famous as $3,4,5$ though

igreen · Answer

Lol.

igreen · Answer

Yep, a = 15 :)

anonymous · Answer

@iGreen, can you check this really quick.

8^2 + b^2 = 10^2

64 + b^2 = 100

100 - 64 = 36

square root of 36 = 6

igreen · Answer

You got it! :D

anonymous · Answer

Alright! Thanks for your help.

igreen · Answer

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