## elizabethann509 3 years ago I don't need an answer, I just need some help on how to do this. Your uncle is making you a desk for you to take to college. One side of the desk is 32 inches and the diagonal length is 36 inches. What is the length of the other side of the desk? I know that you have to use the Pythagorean theorem for this and I know how to find the hypotenuse if I know the measures of the legs. Do I do the exact same thing with this only I'm looking for the measure of the leg? Or is it different?

1. elizabethann509

|dw:1336337420890:dw|

2. amistre64

fill in the parts to the pythag and then rearrange to solve the missing

3. mathdood

well if a^2= b^2+c^2 and you have a and either b or c then just solve for b or c

4. amistre64

a^2 + b^2 = c^2 a^2 = c^2 - b^2

5. elizabethann509

So, normally if I were to be looking for the hypotenuse then the legs would be A and B and the hypotenuse is C? So I rearrange it accordingly to what I know like the equations you just showed me?

6. amistre64

yep

7. elizabethann509

8. amistre64

becasue when you subtract b^2 from each side ... well, .... you subtract it

9. elizabethann509

That doesn't make sense (what you just wrote). Also, I still don't get it. Because it's: a^2 + b^2 = c^2 Why does that become a subtraction sign when it is rearranged?

10. amistre64

well, lets use real numbers 5 + 3 = 8 does 5 = 8 + 3 ?

11. mathdood

because that is how algebra works if you have 4 = 2 + x and you want to figure out x you take 2 from both sides and you get x = 4- 2 this si the same and a b and c are just variables it doesn't matter how you write them just know that when you are adding it is for the hypotenuse and when you are subtracting it is for one of the two sides.

12. amistre64

the equal sign represent balance between the weight of 2 opposing sides 5 + 3 = 8 is balanced and equal ; if we subtract 3 from each side it stays equal -3 -3 ---------- 5 + 0 = 5

13. elizabethann509

Ohh okay! That makes sense now that you showed that example. Thanks :) I'll give it a try and see if I can get it right!

14. amistre64

good luck

15. elizabethann509

Thanks!

16. elizabethann509

Still having some trouble on how to figure this out :/ I fill it in but I would come out with negatives every time with the way I am doing this. I'm doing it like you both said so I'm not sure what I'm doing wrong?

17. elizabethann509

No idea what to do now! :p

18. amistre64

youre most likely mixing up your hypotenuse and side; the negative just means youve got them backwards 5 - 3 = 2 3 - 5 = -2

19. amistre64

just drop the negative and youll be fine

20. amistre64

a^2 = 36^2 - 32^2 a = sqrt(36^2 - 32^2)

21. amistre64

we can also trim down some computations 36 = 9*4 32 = 8*4 (9*4)^2 - (8*4)^2 = 4^2 (9^2 - 8^2) a = 2 sqrt(81-64)

22. elizabethann509

Wow, i was doing that wayyy different i think lol. i was doing 36x36 and 32x32 and i got numbers in the thousand range. so i just multiply it by 2 then? lol

23. amistre64

the more you can simply to begin with, the smaller your calculations will be either way itll turn out the same if you do the mathing right :)

24. elizabethann509

Okay lol. Thank you soo much! I was completely confused but I get it now :)

25. amistre64

youre welcome