Ask your own question, for FREE!
Mathematics 18 Online
OpenStudy (anonymous):

Pythagorean Theorem Help

OpenStudy (anonymous):

well i took a test about the Pythagorean Theorem and my teacher never teached us about the Pythagorean Theorem and i just need help on this

OpenStudy (solomonzelman):

\[a^2+b^2=c^2\] is the theorem. It's used to find the diagonal of the gright triangle. |dw:1389375102485:dw| a and b are the legs of the triangle, b is the hypotenuse.

OpenStudy (solomonzelman):

I meant right triangle not gright, sorry.

OpenStudy (solomonzelman):

So FOR EXAMPLE: |dw:1389375163460:dw| use the theorem, plug in numbers.\[6^2+8^2=c^2\]Solve for c.\[36+64=c^2\]\[100=c^2~~~~~~~->~~~~~c=10\]

OpenStudy (anonymous):

oops If X = 3 units and Y = 12 units, what is the length of Z?|dw:1389375248416:dw|

OpenStudy (anonymous):

thats the triangle

OpenStudy (anonymous):

\[\sqrt{15} \sqrt{153} \sqrt{163}\] 153

OpenStudy (solomonzelman):

\[3^3+12^2=Z^2\]

OpenStudy (solomonzelman):

\[Z=?\]

OpenStudy (anonymous):

yes

OpenStudy (whpalmer4):

No, Z doesn't equal "yes", it equals a number, which you should calculate :-) \[3^2=3*3=\]\[9^2=9*9=\]Add those two numbers together, what do you get?

OpenStudy (anonymous):

3x3=9 and 9x9=81

OpenStudy (anonymous):

sorry 9+9=18 and 3+3= 6

OpenStudy (whpalmer4):

sorry, that should have been \[12^2 = 12*12 = \]no idea where 9 came from!

OpenStudy (anonymous):

LoL

OpenStudy (whpalmer4):

12-3=9, that must be it :-)

OpenStudy (anonymous):

12-3=9 yes its correct

OpenStudy (whpalmer4):

but back to the real problem, what is \[12^2= 12*12 =\]

OpenStudy (anonymous):

so is it 12+12 or 12x12

OpenStudy (whpalmer4):

\(12*12\) is multiplication

OpenStudy (anonymous):

ok 12x12=144

OpenStudy (whpalmer4):

right, so by Pythagorean theorem, \[Z^2 = X^2+Y^2\]and we have determined that \[X^2=3*3=9\]and\[Y^2=12*12=144\]

OpenStudy (whpalmer4):

what does \(Z^2=\) what about \(Z=\) (which is what the problem requests we find)

OpenStudy (anonymous):

hmm z must be 144 but i might be rong

OpenStudy (whpalmer4):

No, \[Z^2 = X^2+Y^2 = 9+144 = \]

OpenStudy (anonymous):

153

OpenStudy (whpalmer4):

Right. So if \[Z^2=153\]what does \[Z=\]

OpenStudy (anonymous):

153 or

OpenStudy (anonymous):

am i rong?

OpenStudy (whpalmer4):

Well, if Z*Z = 153, can Z=153?

OpenStudy (whpalmer4):

I haven't made a close study of the number 153, but I think the answer is no :-)

OpenStudy (anonymous):

so we might have to divide

OpenStudy (whpalmer4):

we need the square root of 153, or \(\sqrt{153}\) the square root of some number is defined as another number, which when multiplied by itself, gives you the first number. For example, the square root of 4 is 2, because 2*2 = 4.

OpenStudy (whpalmer4):

\[\sqrt{x}*\sqrt{x} = x\] \[\sqrt{153}*\sqrt{153} = 153\] So if \[Z^2=153\]then \[Z=\sqrt{153}\]

OpenStudy (anonymous):

ok so thats the answer Z\[\sqrt{153}\]

OpenStudy (whpalmer4):

notice that there was a "trap" answer of 153 in your answer choices, put there to catch careless students who just added X^2 and Y^2 and forgot that that gives them Z^2, not Z

OpenStudy (whpalmer4):

and \[\sqrt{15}\]was probably intended to catch people who forgot to square X and Y before adding them...

OpenStudy (anonymous):

there fore thats not the answer?

OpenStudy (whpalmer4):

the correct answer is the one we found: \[Z = \sqrt{153}\]

OpenStudy (anonymous):

ok so it was but you where giving me a explanation of the answer right?

OpenStudy (whpalmer4):

2 of the other answers are answers you get if you make various predictable mistakes. I'm not sure how you might get \[Z = \sqrt{163}\]but I'm sure there's some student who could manage to do it :-) Yes, I wanted you to see the importance of working carefully and not just grabbing the first answer that appears to have a number you got...

OpenStudy (anonymous):

right right and i live teachers like you :) how many can you do?

OpenStudy (whpalmer4):

let's do another one!

OpenStudy (anonymous):

:D ok

OpenStudy (anonymous):

If X = 10 cm and Y = 10 cm, what is the length of Z? |dw:1389377822260:dw|

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!