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Inscribed circle

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by rommysingh » Thu Aug 06, 2015 6:55 pm
For the triangle shown above, where A, B and C are all points on a circle, and line segment AB has length 18, what is the area of triangle ABC?

(1) Angle ABC measures 30°.

(2) The circumference of the circle is 18.
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Source: — Data Sufficiency |

by Uva@90 » Thu Aug 06, 2015 10:45 pm
rommysingh wrote:For the triangle shown above, where A, B and C are all points on a circle, and line segment AB has length 18, what is the area of triangle ABC?

(1) Angle ABC measures 30°.

(2) The circumference of the circle is 18.
Image
Hi Rommy Singh,

Here they are testing the below rule,

Angle formed through the diameter of the circle is 90 degree.

Apply the above rule.

Thanks.
Regards,
Uva.
Known is a drop Unknown is an Ocean
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by Jim@StratusPrep » Fri Aug 07, 2015 8:32 am
Statement 2 is supposed to say the circumference is 18Ï€, correct?

Assuming so...

1) We don't know anything about the triangle with just 1 angle and 1 side
2) We know now that angle C is 90 based off the rule Uva mentioned, but we don't know anything else

Together - Now we know that this is a 30-60-90 triangle; with 1 side, we can get all the side and the area.


C
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