Inscribed Square

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Inscribed Square

by skalevar » Sat Sep 25, 2010 10:29 am
Rectangle ABCD is inscribed in circle P. What is the area of circle P?

(1) The area of rectangle ABCD is 100.

(2) Rectangle ABCD is a square.


I said A because if a rectangle ABCD is inscribed in a circle, it must be a square. If it is a square, it's side must be 10, and it's diagonal 10(root2). Therefore, we can calculate the area of the circle.

However, official answer says C.

Why is my reasoning incorrect?
Source: — Data Sufficiency |

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by kvcpk » Sat Sep 25, 2010 11:15 am
skalevar wrote:Rectangle ABCD is inscribed in circle P. What is the area of circle P?

(1) The area of rectangle ABCD is 100.

(2) Rectangle ABCD is a square.


I said A because if a rectangle ABCD is inscribed in a circle, it must be a square. If it is a square, it's side must be 10, and it's diagonal 10(root2). Therefore, we can calculate the area of the circle.

However, official answer says C.

Why is my reasoning incorrect?
A rectangle other than a square can be inscribed in a circle. Just think again.
"Once you start working on something,
don't be afraid of failure and don't abandon it.
People who work sincerely are the happiest."
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by skalevar » Sat Sep 25, 2010 11:52 am
you're right. thanks