One side of a square is inclined at an acute angle $\alpha$ with the positive $x-$axis, and one of its extremities is at the origin. If the remaining three vertices of the square lie above the $x-$axis and the side of a square is $4$, then the equation of the diagonal of the square which is not passing through the origin is
$(cos\, \alpha + sin\, \alpha) x + (cos\, \alpha - sin\, \alpha) y = 4$
$(cos\, \alpha + sin\, \alpha) x - (cos\, \alpha - sin\, \alpha) y = 4$
$(cos\, \alpha - sin\, \alpha) x + (cos\, \alpha + sin\, \alpha) y = 4$
$(cos\, \alpha - sin\, \alpha) x - (cos\, \alpha + sin\, \alpha) y = 4 cos\, 2\alpha$
Area of the rhombus bounded by the four lines, $ax \pm by \pm c = 0$ is :
If the sum of the distances of a point from two perpendicular lines in a plane is $1$, then its locus is
In a triangle $ABC,$ side $AB$ has the equation $2 x + 3 y = 29$ and the side $AC$ has the equation , $x + 2 y = 16$ . If the mid - point of $BC$ is $(5, 6)$ then the equation of $BC$ is :
Let the equation 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