Hello. Okay a couple questions here...
1. In the geometry medium drill sets, (pg 206 #11), the question asks for you to determine possible side of a triangle with the longest length of 10. I do not understand why the option can't be (E) 9. If you use the length rule (sum of any two sides will always be greater than the third side length) shouldn't 9 count?
2, Okay going backwards.. easy drill sets (pg 193 #13), quant comparison trying to figure out the area of the inscribed rectangle verse 80. Diameter of the circle is 12. I understand everything up to the point on why you take 12 and divide by square root 2 to get 6 square root 2. How did you get that?
Thanks!
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- kristen.igo
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- tommywallach
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Re: Ge0metry
Hey Kristen!
In the future, please post each question you have as an individual post, and title it with the page and question # you're asking about (I'll change this one) so that other people can reference.
Pg. 206, #11
The rule in question here is that any side of a triangle must be larger than the difference between the other two sides and smaller than the sum of the other two sides.
What you're forgetting is that the question says the sides have to be integers. If one side here is 10 and one is 9, then the third side must be between 19 and 1. It cannot be 1, however.
Pg. 193, #13
In this case, it's simply because we're imagining the rectangle is actually a square. The sides of any square are defined by the relationship x:x:x*rt.2 (where x*rt.2 is the hypotenuse). In this case, we know that hypotenuse is 12. So if 12 = x*rt. 2, then x (the other sides) = 12 / rt. 2.
Make sense?
-t
In the future, please post each question you have as an individual post, and title it with the page and question # you're asking about (I'll change this one) so that other people can reference.
Pg. 206, #11
The rule in question here is that any side of a triangle must be larger than the difference between the other two sides and smaller than the sum of the other two sides.
What you're forgetting is that the question says the sides have to be integers. If one side here is 10 and one is 9, then the third side must be between 19 and 1. It cannot be 1, however.
Pg. 193, #13
In this case, it's simply because we're imagining the rectangle is actually a square. The sides of any square are defined by the relationship x:x:x*rt.2 (where x*rt.2 is the hypotenuse). In this case, we know that hypotenuse is 12. So if 12 = x*rt. 2, then x (the other sides) = 12 / rt. 2.
Make sense?
-t
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