M11 #32

Question

If a square is inscribed in a circle of radius 4, what is the area of the square?

* 8
 * 16
 * 32
 * 48
 * 64

The diameter of the circle is the diagonal of the square. The side of the square is  2*\sqrt{8}  , therefore the area of the square is 32. The correct answer is C.

How do you get 2*sqrt(8) for each side? I was getting 4 which is x^2+x^2=8^2, so x=4. Please explain how do solve for the sides using Pythagorean theorem.

sdrandom1 · Answer

If a square is inscribed in a circle of radius 4, what is the area of the square?

* 8
* 16
* 32
* 48
* 64

The diameter is 8 = Diagonal of the square.
But diagonal of a square with side a  = a\sqrt{2} 
Hence if  8 = a\sqrt{2} , then we can see that side of the sqaure  = a = \frac{8}{\sqrt{2}} 
Therefore, area  = a^2 = \left(\frac{8}{\sqrt{2}}\right)^2 = 32

I3igDmsu · Answer

Still not understanding. Any help?
I think its a notation problem above. what does the /\ mean?

I3igDmsu · Answer

Got it now, the math formulas weren't working, its easier to understand now above. Thanks sdrandom1.

dzyubam · Answer

I've edited the post above so that math expressions work.

In order for the math expressions to work fine, one needs to enclose the whole expression in the "m" tag, which is next to the "fraction" tag in the edit page. This won't work (without the "m" tag):

[square_root]x^2 -2x +1[/square_root] = [square_root](x-1)^2[/square_root] = |x-1| 
\sqrt{x^2 -2x +1} = \sqrt{(x-1)^2} = |x-1|

This will work (just add the "m" tag):

[m][square_root]x^2 -2x +1[/square_root] = [square_root](x-1)^2[/square_root] = |x-1|[/m] 
 \sqrt{x^2 -2x +1} = \sqrt{(x-1)^2} = |x-1|

Remember to use only one "m" tag for the whole expression, no need to enclose every single unit in it.

Hope this helps.

M11 #32

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