MHB Incircle and circumscribed circle prove :d=√(R(R−2r))

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The discussion focuses on proving the relationship between the distance \( d \) between the circumcenter \( O \) and incenter \( I \) of triangle \( ABC \), and the radii \( R \) and \( r \) of the circumcircle and incircle, respectively. The formula to be proven is \( d = \sqrt{R(R - 2r)} \). Participants explore geometric properties and relationships within triangle \( ABC \) that lead to this equation. The proof involves understanding the positioning of the incenter and circumcenter relative to the triangle's vertices and sides. The conclusion emphasizes the significance of this relationship in triangle geometry.
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$\triangle ABC$ with its incircle $I$ (radius $r$)
and circumscribed circle $O$ (radius $R$)
the distance between points $O$(circumcenter) and $I$(incenter) is $d$
prove:$d=\sqrt {R(R-2r)}$
 
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Albert said:
$\triangle ABC$ with its incircle $I$ (radius $r$)
and circumscribed circle $O$ (radius $R$)
the distance between points $O$(circumcenter) and $I$(incenter) is $d$
prove:$d=\sqrt {R(R-2r)}$
$d=\sqrt{R^2-2Rr}$
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