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by kajcha » Tue Sep 18, 2007 2:05 pm
I think there is a property that the radius of a circle, inscribed in an equilateral triangle is equal to height/3

So height of eq triangle = root3*10/2 = 5root3

radius of the circle = 5root3/3

area of circle = pi*(5root3/3)^2 = 25pi/3
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by mtg123 » Thu Sep 20, 2007 5:57 am
Radius of circle inscribed in any triangle
= area of triangle/ semi perimeter of triangle

Radius of circle inscribed in an equilateral triangle
= a/ (2 * rt 3) where a- side of triangle


Radius of circle circumscribed in any triangle
= (a*b*c) / (4 *area of triangle) where a,b,c -3 sides of triangle

Radius of circle circumscribed in an equilateral triangle
= a/ rt 3 where a- side of triangle
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by mtg123 » Thu Sep 20, 2007 5:58 am
Radius of circle inscribed in any triangle
= area of triangle/ semi perimeter of triangle

Radius of circle inscribed in an equilateral triangle
= a/ (2 * rt 3) where a- side of triangle


Radius of circle circumscribed in any triangle
= (a*b*c) / (4 *area of triangle) where a,b,c -3 sides of triangle

Radius of circle circumscribed in an equilateral triangle
= a/ rt 3 where a- side of triangle
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by niks_01.27 » Thu Sep 20, 2007 7:45 pm
Inscribed circle radius = a x root(3)/6; a = side of equilatral triangle.

So area of circle = pi x {10 x root(3) / 6}^2 = 25 pi / 3.
regards
niks...
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