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Analytical Geometry

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5 Jan 2009 11:21:43 IST

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a question of circle

Engineering Entrance , JEE Main , JEE Advanced , Mathematics , Analytical Geometry

find area of equilateral triangle inscribed in the circle

Comments (3)

Prakhar Banga

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6 Jan 2009 09:02:34 IST

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Let the triangle be ABC and the centre of the circle be O.

Therefore, angle AOB = 120 degrees and angle ABO = 30 degrees.

So By sine rule

AO is the radius. Let it be r. AB is the side of the triangle. Let it be a.

So a = r.

That means the radius of the circle is

The side a is therefore .

The area of the triangle is =

Sagar Saxena

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7 Jan 2009 00:03:14 IST

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hello dear..

the radius of the circle with given equation is :

r = (g² + f² - c)^1/2

for equitlateral traingle

r = a / root(3)

area of traingle = root(3) / 4 * a²

now solve it ,you will get the answwer

Sagar Saxena

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Posts: 8064

7 Jan 2009 00:04:04 IST

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cheers.............

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