Explanation:
D Given, centroid \(=(6,6,3)\)
Let, equation of plane be -
\(\frac{\mathrm{x}}{\mathrm{a}}+\frac{\mathrm{y}}{\mathrm{b}}+\frac{\mathrm{z}}{\mathrm{c}}=1\)
Coordinate of \(x, y\) and \(z\) axes are \((a, 0,0),(0, b, 0)\) and \((0,0, c)\) centroid of triangle \(\left(\frac{a}{3}, \frac{b}{3}, \frac{c}{3}\right)\)
Here, \((\mathrm{p}, \mathrm{p}, \mathrm{r})=(6,6,3)\) (given)
\(\text { centroid }\left(\frac{\mathrm{a}}{3}, \frac{\mathrm{b}}{3}, \frac{\mathrm{c}}{3}\right)=(6,6,3)\)
(given)
\(\mathrm{a}=18, \mathrm{~b}=18, \mathrm{c}=9\)
Put value in (i)
\(\frac{x}{18}+\frac{y}{18}+\frac{z}{9}=1\)
\(x+y+2 z=18 \text { or } x+y+2 z-18=0\)