Question

If the origin is the centroid of triangle ABC with vertices A(a, 1, 3), B(-2, b, - 5) and C(4, 7, c), find the values of a, b, c.

Answer 1

Since, centroid of a triangle is found by

The points are A(a,1,3) and B(-2, b, -5), and its centroid is (0, 0, 0) and its third vertex C(4,7,c). 

Using the formula, we get

Equating it with the coordinates of centroid, we get

c = 2 

therefore, a = -2, b = - 8, c = 2.