Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Geometry Help

  1. Oct 17, 2004 #1
    Hello everyone,

    I need help with a couple of problems, right now I'm focusing on number 25.

    http://img24.exs.cx/img24/2291/probs.gif

    Also, if any of you have time, could you please tell me if I have missed any so far. Thanks.

    22. A= 3768.2 units^2
    23. A= 25.3 units^2
    24. A= 5.4 units^2

    And now if I could just get some help with the others...
     
  2. jcsd
  3. Oct 17, 2004 #2

    arildno

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    Dearly Missed

    Now, you've got a square with the diagonal given, right?
    So, what's your problem, exactly?
     
  4. Oct 17, 2004 #3
    I need help going about finding the lenght of the sides
     
  5. Oct 17, 2004 #4

    arildno

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    Dearly Missed

    Sure enough, but:
    1) You've got a square, right?
    So, how does then the vertical side compare in length to the horizontal side?
    2) Try to set up Pythagoras' theorem with the diagonal as the hypotenuse..
     
  6. Oct 17, 2004 #5
    The lenght of all the sides would be 7.5 sqrt(2) right?
     
  7. Oct 17, 2004 #6
    We have C from Pythagoras' therom
    [tex] a^2 + b^2 = c^2 [/tex]

    however for a square
    [tex] a=b [/tex]

    so
    [tex] a^2 + a^2 = c^2 [/tex]
    [tex] 2a^2=c^2 [/tex]

    [tex] 2a^2=15^2 [/tex]
    [tex] 2a^2=225 [/tex]


    since area of a square is just a*b and a=b
    area equals a*a or a^2 so divide the two out
    [tex] a^2=\frac{225}{2} [/tex]
     
  8. Oct 17, 2004 #7
    I believe 22 is wrong
    23 is right rounded
    24 is right rounded
     
    Last edited: Oct 17, 2004
  9. Oct 17, 2004 #8
    22. by law of sines

    [tex]\frac {73}{\sin{\theta}}=\frac{x}{\sin{\theta}} [/tex]

    therefore must also be 73
    73*73*.5 = 2664.5
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook