The equations of the sides AB, BC and CA of a triangle ABC are 2x + y = 0, x + py = 39 and x – y = 3, respectively and P(2, 3) is its circumcentre. Then which of the following is NOT true?
\((AC)^2 = 9p\)
\((AC)^2 + p^2 = 136\)
\(32 < area (ΔABC)<36\)
\(34<area(ΔABC)<38\)
The correct answer is (D) : \(34<area(ΔABC)<38\)
Intersection of 2x + y = 0 and x – y = 3 :A(1, –2)

Equation of perpendicular bisector of AB is
x – 2y = –4
Equation of perpendicular bisector of AC is
x + y = 5
Point B is the image of A in line x – 2y + 4 = 0
which can be obtained as
\(B(\frac{-13}{5},\frac{26}{5})\)
Similarly vertex C : (7, 4)
Equation of line BC : x + 8y = 39
So, p = 8
\(AC = \sqrt{(7-1)^2+(4+2)^2}\)
\(= 6\sqrt2\)
Area of triangle ABC = 32.4
Let the lines $L_1 : \vec r = \hat i + 2\hat j + 3\hat k + \lambda(2\hat i + 3\hat j + 4\hat k)$, $\lambda \in \mathbb{R}$ and $L_2 : \vec r = (4\hat i + \hat j) + \mu(5\hat i + + 2\hat j + \hat k)$, $\mu \in \mathbb{R}$ intersect at the point $R$. Let $P$ and $Q$ be the points lying on lines $L_1$ and $L_2$, respectively, such that $|PR|=\sqrt{29}$ and $|PQ|=\sqrt{\frac{47}{3}}$. If the point $P$ lies in the first octant, then $27(QR)^2$ is equal to}