Question (nov. 25)

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Question (nov. 25)

by bacali » Tue Nov 25, 2008 8:12 am
It took me two tries to get this but a great question.

In the coordinate plane, a circle has center (2, -3) and passes through the point (5, 0). What is the area of the circle?


A. 3π
B. 3√2π
C. 3√3π
D. 9π
E. 18π


oa: e
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Re: Question (nov. 25)

by iamcste » Tue Nov 25, 2008 8:28 am
bacali wrote:It took me two tries to get this but a great question.

In the coordinate plane, a circle has center (2, -3) and passes through the point (5, 0). What is the area of the circle?


A. 3π
B. 3√2π
C. 3√3π
D. 9π
E. 18π


oa: e

Using distance forumla of Cordinate Geometry

|P1P2| = sq rt ( (x2 − x1) power 2+ (y2 − y1) power2 )

Refer the PPT for additional details

radius= sq rt 18

Area= pi* 18

IMO E
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by mals24 » Tue Nov 25, 2008 8:33 am
Image

In the figure above.

AB = 5-2 = 3

BC = 3

AC = sqrt18 (use Pythagoras theorem)

AC is also the radius of the circle

Hence area = 18*pi