Question

If the origin is the centroid of the ΔPQR with vertices A(a,2, b), B(-2, 5b, -12) and C(4, 8, 2c).

Answer 1

Given, A(a,2, b), B(-2, 5b, -12) and C(4, 8, 2c). are the vertices of ΔABC

0(0, 0, 0) is the centroid of ΔABC

⇒ a = −2 

⇒ b = −2

⇒ −2 + 2c − 12 = 0 

⇒ c = 7 

∴ a = −2, b = −2, c= 7