right triangles - Problem solving

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right triangles - Problem solving

by ccassel » Thu Mar 24, 2011 11:03 am
Hi All,

Would anyone be able to explain the answer to the following question?

Which of the following groups of numbers could be the lengths of the sides of a right triangle?

I. 1, 4, root17
II. 4, 7, root11
III. 4, 9, 6

Answer is A: "I" only

Thanks,
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by Night reader » Thu Mar 24, 2011 11:17 am
the unique property for ALL right triangles is Pythagorean theorem C^2 (hypotenuse side squared) = A^2 + B^2 (squared non-hypotenuse sides' sum). Let's see III. 4,9,6 - please note it's not possible to have 9^2=4^2+6^2. And II. 7^2 = 4^2 + 11 is also not possible. But, note I. 1,4, root17 --> 17=1^2 + 4^2 Correct
ccassel wrote:Hi All,

Would anyone be able to explain the answer to the following question?

Which of the following groups of numbers could be the lengths of the sides of a right triangle?

I. 1, 4, root17
II. 4, 7, root11
III. 4, 9, 6

Answer is A: "I" only

Thanks,
My knowledge frontiers came to evolve the GMATPill's methods - the credited study means to boost the Verbal competence. I really like their videos, especially for RC, CR and SC. You do check their study methods at https://www.gmatpill.com

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by ccassel » Thu Mar 24, 2011 11:31 am
Thanks, that makes sense but should it match one of the pathagorean triplets? That is where I went off path.

3:4:5
5:12:13
1:1:root2
1:root3:2
7:24:25

Thanks again!

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by Night reader » Thu Mar 24, 2011 12:28 pm
what you list below are the different side relationships in right triangles given their respective angle properties, i.e. 45`-45`-90 --> 1-1-Sqrt(2) OR 30-60-90 --> 1-Sqrt(3)-2, also the sides C^2= A^2 + B^2. These are all correct, BUT leave out the answer choices in your question.
ccassel wrote:Thanks, that makes sense but should it match one of the pathagorean triplets? That is where I went off path.

3:4:5
5:12:13
1:1:root2
1:root3:2
7:24:25

Thanks again!
My knowledge frontiers came to evolve the GMATPill's methods - the credited study means to boost the Verbal competence. I really like their videos, especially for RC, CR and SC. You do check their study methods at https://www.gmatpill.com

Master | Next Rank: 500 Posts
Posts: 118
Joined: Wed Mar 16, 2011 1:44 pm
Location: Canada
Followed by:2 members
GMAT Score:530

by ccassel » Thu Mar 24, 2011 2:30 pm
I see the relationship now. Thanks.