The figure below shows a triangle ABC with the circumradius R, the inradius r. If \(d, e, f\) are the distances from the midpoints of arcs AB, AC, BC to the sides BC, BC, and AC, respectively, prove that \(d+e+f=2(R+r)\).
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Ten problems: 1411-1420
Inradius, Incenter, Incircle
Circle Tangent Line
HTML5 and Dynamic Geometry
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