Question

The coordinates of the centroid of triangle ABC where A, B, C are the points of intersection of the plane 6x + 3y -2z = 18 with the coordinate axes are

• A. (1, 2, -3)
• B. (-1, 2, 3)
• C. (-1, -2, -3)
• D. (1, -2, 3)

Answer 1

The correct option is A (1, 2, -3)

$6x+3y–2z=18$
$\Rightarrow \frac{x}{3}+\frac{y}{6}+\frac{z}{-9}=1$
Coordinates of A, B, C are respectively
(3, 0, 0), (0, 6, 0) and (0,0, -9)
$\therefore$ Centroid of $\Delta ABC$ is $(\frac{3}{3},\frac{6}{3},\frac{-9}{3})$
ie, (1, 2, -3).