Consider `/_\ABC`. Let I bet he incentre and a,b,c be the sides of the triangle opposite to angles A,B,C respectively. Let O be any point in the plane of `/_\ABC` within the triangle. AO,BO and CO meet the sides BC, CA and AB in D,E and F respectively. `avec(IA)=bvec(IB)+cvec(IC)=` (A) `-1 (B) 0 (C) 1 (D) 3`

Consider /_\ABC. Let I bet he incentre and a,b,c be the sides of the triangle opposite to angles A,B,C respectively. Let O be any point in the plane of /_\ABC within the triangle. AO,BO and CO meet the sides BC, CA and AB in D,E and F respectively. (OD)/(AD)+(OE)/(BE)+(O)/(CF)= (A) 3/8 (B) 1 (C) 3/2 (D) none of these

Consider /_\ABC . Let I bet he incentre and a,b,c be the sides of the triangle opposite to angles A,B,C respectively. Let O be any point in the plane of /_\ABC within the triangle. AO,BO and CO meet the sides BC, CA and AB in D,E and F respectively. If 3vec(BD)=2vec(DC) and 4vec(CE)=vec(EA) then the ratio in which divides vec(AB) is (A) 3:4 (B) 3:2 (C) 4:1 (D) 6:1

O is any point in the plane of the triangle ABC,AO,BO and CO meet the sides BC,CA nd AB in D,E,F respectively show that (OD)/(AD)+(OE)/(BE)+(OF)/(CF)=1.

O is any point inside a triangle ABC. The bisector of /_AOB,/_BOC and /_COA meet the sides AB,BC and CA in point D, and F respectively.Show that ADxBExCF =DBxECFA

Find the area of triangle ABC , the midpoints of whose sides AB, BC and CA are D(3,-1), E(5, 3) and F(1,-3) respectively.

In Delta ABC,a,b,c are the opposite sides of the angles A,B and C respectively,then prove (sin B)/(sin(B+C))=(b)/(a)