Q. Let the equations of two sides of a triangle be $3x - 2y + 6 = 0$ and $4x + 5y - 20 = 0$. If the orthocentre of this triangle is at $(1, 1)$, then the equation of its third side is :
Solution:
Equation of $AB$ is $3x - 2y + 6 = 0$
Equation of $AC$ is $4x + 5y - 20 = 0$
Equation of $BE$ is $2x + 3y - 5 = 0$
Equation of $CF$ is $5x - 4y - 1 = 0$
$\Rightarrow $ Equation of BC is $26x - 122y = 1675$
