Please if someone would be nice enough to help because im failing geometry and im trying to bring my grade up and i only have today! A window frame that seems rectangular has height 408 cm, length 306 cm, and one diagonal with length 525 cm. Is the window frame really rectangular? Explain.

Question

anonymous · Answer

A is  Length so A^2 would be 306^2; B is Height so B^2 would be 408^2 

 The Pythagorean Theorem is A^2 + B^2 = C^2

anonymous · Answer

it would be the idea that rectangles have right angles

so you would use the pythagorean theorem to test this

a^2 + b^2 = c^2

c = sqrt ( 408^2 + 306^2 )  = ?

would it equal  525 ?

elisaneedshelp · Answer

why square root?

anonymous · Answer

because   c^2 = a^2 + b^2   right? :)
then to get c  alone from   c^2
you would  sqrt both sides

so   c = sqrt ( a^2 + b^2 )

elisaneedshelp · Answer

can you give me an example :) lol sorry :/

anonymous · Answer

it's alright  :)
like if you wanted to check if   sides  3 and 4
made a rectangle with  diagonal  6

then   a^2 + b^2 = c^2

c = sqrt (a^2 + b^2)
   =  sqrt ( 3^2 + 4^2 )
   =  ?
would it equal 6 ?
if it does, it is a rectangle.
if it does not, then it is not a rectangle

elisaneedshelp · Answer

Nope it equals 5 so then its not a rectangle

anonymous · Answer

yes :)

so then you would use the same idea for your own question :)

elisaneedshelp · Answer

thank you :) can you help me with this one , I have to find Y

elisaneedshelp · Answer

Omg thanks my first testimonial :'D

anonymous · Answer

pythagorean theorem

c would = 25
a would = -7

so   25^2 = (-7)^2 + y^2

solve for y

elisaneedshelp · Answer

$$-7^{2}+b ^{2}=25^{2}$$
$$-49+b ^{2}=625$$
+49            +49
            b=   674

anonymous · Answer

it was   7^2 + b^2 = 25^2
     so    49 + b^2 = 625
           -49               -49
                     b^2 = 576
so    b = sqrt   576  = ?

anonymous · Answer

ah right, I saw what you did

when  the negative is in the parenthesis, it is included in the squaring

so   (-7)^2 = 49

which is different from   - (7)^2 = -49

we wanted   (-7)^2 = 49

elisaneedshelp · Answer

But when i put -7^2 it gave me -49

anonymous · Answer

(-7) times (-7) = 49
because a negative times a negative = positive

elisaneedshelp · Answer

Ohhh..........i didnt know it had to be in ( )

anonymous · Answer

@Emz.Yaoi i just want to say. You should considering becoming a teacher lol

elisaneedshelp · Answer

Lol ikr

anonymous · Answer

Thanks @BeautifulSoulღ  :)  I'll be an ambassador of this website soon :P
that'll be good enough for now

anonymous · Answer

:)

anonymous · Answer

@ElisaNeedsHelp so do you understand how to do your problem now? :)

elisaneedshelp · Answer

Yes :) i was just copying down the other problem that you had explained to me

anonymous · Answer

coolios ^_^