If the vertices A,B,C of a triangle ABC are (1,2,3),(-1,0,0) ,(0,1,2) , respectively, then find `angleABC`.

If the vertices A, B, C of a triangle ABC are (1, 2, 3), (1, 0, 0), (0, 1, 2) , respectively, then find /_A B C . [ /_A B C is the angle between the vectors vec( B A) and vec (B C) .

If the vectors A ,B ,C of a triangle A B C are (1,2,3),(-1,0,0),(0,1,2), respectively then find /_A B Cdot

The coordinates of the vertices Ba n dC of a triangle A B C are (2, 0) and (8, 0), respectively. Vertex A is moving in such a way that 4tanB/2tanC/2=1. Then find the locus of A

The vertices of a triangle ABC are A(0, 0), B(2, -1) and C(9, 2) , find cos B .

The vertices of a triangle are A(1, 3, 2), B(2, -1, 3) and C(-1, 4, 2). Find the angle A.

If vertices of a triangle are (a,1,3),(-2,b,-5)&(4,7,c) and centroid is (0,0,0).Find a,b,c

In triangle ABC, the co-ordinates of vertices A, B and C are (4, 7), (-2, 3) and (0, 1) respectively. Find the equation of median through vertex A. Also, find the equation of the line through vertex B and parallel to AC.

If the circumcentre of triangle ABC is (alpha,beta,gamma) where A, B, C are ((1, 0, 0) (0, 1, 0) and (0,0,1) respectively then alpha+beta+gamma+=1 (b) alpha=beta gamma=1/3 (d) alpha=1

Find the equation of the side BC of the triangle ABC whose vertices are A(-1,-2),\ B(0,1)a n d C(2,0) respectivley. Also, find the equation of the median through A(-1,\ -2)dot

In a triangle, ABC, the equation of the perpendicular bisector of AC is 3x - 2y + 8 = 0 . If the coordinates of the points A and B are (1, -1) & (3, 1) respectively, then the equation of the line BC & the centre of the circum-circle of the triangle ABC will be