MathDB

1

Part of 2009 India IMO Training Camp

Problems(1)

India TST 2009 DAY 1:PROBLEM 1

Source: easiest

5/14/2009
Let ABC ABC be a triangle with ∠A=60∘ \angle A = 60^{\circ}.Prove that if T T is point of contact of Incircle And Nine-Point Circle, Then AT=r AT = r, r r being inradius.
geometrytrigonometrygeometric transformationhomothetyratiocircumcircleincenter