Anonymous
Anonymous asked in Science & MathematicsMathematics · 1 decade ago

I need help with geometry proofs?

I'm in 9th grade and I'm in geometry. I don't understand how to do geometry proofs, does anyone know how to explain them to me or know a good website I can go to?

Update:

I've already tried google and other search engines, they aren't bringing up what I need. That's why I'm asking.

4 Answers

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  • 1 decade ago
    Favorite Answer

    if your looking for a basic primer on how to go about proving mathematical theorems you would do well to look here

    http://zimmer.csufresno.edu/~larryc/proofs/proofs....

    if your instead looking for information on basic geometric constructions with compass and straight edge your best bet would be

    http://www.mathopenref.com/tocs/constructionstoc.h...

    the best advice i can give you is to remember to think outside the box.

    i know it sounds cliche but math really is the are where abstract thought is both the most useful and the most often ignored.

    for example if you're looking to balance an equation where the RHS looks nothing like the LHS you might try multiplying either side by a convenient form of 1, the good old multiplicative Identity.

    for example prove that

    4a-3a+3(b-(a+b))greater than or equal to (a+b)

    at first glance this may look daunting (or it may look trivial) but if you multiply the RHS by (4-3) and instead of collecting the 3 and 4 together foil it out... it will become obvious that the two sides are identical. therefore they have to fit the constraint of being GTOET. in this little example you could have easily figured this out by collecting like terms on the LHS, but this could easily be a sticking point in the middle of a long complicated proof. also remember that adding zero is always allowed in any form that makes things easier (or harder if you choose incorrectly ;-)

    this is quite obvious if you remember the difference of squares

    a^2 -b^2=(a+b)(a-b)

    which is equivalent to a^2 +(-ab +ab) -b^2

    i think you see the pattern. look for little tricks like this when you get to sticking point and you should find the answer easier. if you have specific questions you can contact me directly on here throught the mail feature.

    hope this helps

    Source(s): Senior Mathematics Major at Thomas More College, Ky
  • Anonymous
    1 decade ago

    In Google, enter Geometry.

  • ~~
    Lv 4
    1 decade ago

    im in 9th grade too, u have 2 do it in 2 column proofs.its sorta hard at first, but then u get used to it.the teacher will go fast at first, but ull get it dont worry

    Source(s): SANA
  • Anonymous
    1 decade ago

    just go to www.yahoo.ca, www.google.com or www.ask.com and type in geometry i worked for me hope it works for you.

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