Guys, please help me,
I am brushing my math skills these days with Kaplan Gmat math book - and have a trouble to find the way to solve the following.
We have a n acute triangle with sides 1 and 3, need to find hypotenuse (third side). I applied Pythagorean theorem- it does not match my answer. I do not why and the book did not provided explanation to this question. only the answer 8 square root. Please heeeeeeeeeeeeeeeeeeeeeelpppppppp [/spoiler][/list]
geometry : acute triangle
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- Gurpinder
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Can you post the exact question please.khilolik wrote:Guys, please help me,
I am brushing my math skills these days with Kaplan Gmat math book - and have a trouble to find the way to solve the following.
We have a n acute triangle with sides 1 and 3, need to find hypotenuse (third side). I applied Pythagorean theorem- it does not match my answer. I do not why and the book did not provided explanation to this question. only the answer 8 square root. Please heeeeeeeeeeeeeeeeeeeeeelpppppppp [/spoiler][/list]
"Do not confuse motion and progress. A rocking horse keeps moving but does not make any progress."
- Alfred A. Montapert, Philosopher.
- Alfred A. Montapert, Philosopher.
- Gurpinder
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You cannot use Pythagorean theorem directly - this is an acute triangle.
Do it like this (attached image).
Now calculate the missing side for triangle A first by using Pythagorean theorem.
.5^2+b^2=3^2
b^2=8.75
Now solve for triangle B.
.5^2+8.75=c^2
.25+8.75=c^2
9=c^2
c=3.
Therefore the missing side y = 3.
Do it like this (attached image).
Now calculate the missing side for triangle A first by using Pythagorean theorem.
.5^2+b^2=3^2
b^2=8.75
Now solve for triangle B.
.5^2+8.75=c^2
.25+8.75=c^2
9=c^2
c=3.
Therefore the missing side y = 3.
"Do not confuse motion and progress. A rocking horse keeps moving but does not make any progress."
- Alfred A. Montapert, Philosopher.
- Alfred A. Montapert, Philosopher.
- Stuart@KaplanGMAT
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Hi,Gurpinder wrote:You cannot use Pythagorean theorem directly - this is an acute triangle.
Do it like this (attached image).
Now calculate the missing side for triangle A first by using Pythagorean theorem.
.5^2+b^2=3^2
b^2=8.75
Now solve for triangle B.
.5^2+8.75=c^2
.25+8.75=c^2
9=c^2
c=3.
Therefore the missing side y = 3.
the only reason you got y=3 is because you actually assumed that y=3 earlier in your math.
By having the height bisect the "1" side, you're assuming that it's an isosceles triangle; of course when you assume it's an isosceles triangle you'll get y=3.
Unfortunately I don't have a copy of the workbook handy - I'd need to see the exact question to give you the proper solution.
Stuart Kovinsky | Kaplan GMAT Faculty | Toronto
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- Gurpinder
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Oh,
hmmm.....Thanks.
Can you please post your explanation when you get a chance?
You can't use the sine law right?
Thanks,
hmmm.....Thanks.
Can you please post your explanation when you get a chance?
You can't use the sine law right?
Thanks,
"Do not confuse motion and progress. A rocking horse keeps moving but does not make any progress."
- Alfred A. Montapert, Philosopher.
- Alfred A. Montapert, Philosopher.
thanks guys for helping, I think i have to explain the question in details. The answer is 8 with radical sign. The picture has acute triangle with sides - x=1, z=3, y=?? -where y is hypotenuse. Sorry can't provide the question from the book- i need to scan it. but it has exactly the same image of a triangle (see the link) I right side is equal to 1, base is equal to 3 hypotenuse y ?
https://www.regentsprep.org/regents/math ... /stri2.gif
https://www.regentsprep.org/regents/math ... /stri2.gif