If the sum of the slopes of the lines represented by the equation $x^2 - 2xy \tan A - y^2 = 0$ is $4$,then $\angle A = $

If the slope of one of the two lines represented by $\frac{x^2}{a} + \frac{2xy}{h} + \frac{y^2}{b} = 0$ is twice that of the other,then $ab : h^2 = $

The equation $r^2 \cos^2 \left(\theta - \frac{\pi}{3}\right) = 2$ represents

If the slopes of the lines represented by $K x^2 + 5 x y + y^2 = 0$ differ by $1$,then $K =$

The quadrilateral formed by the pairs of lines $xy+x+y+1=0$ and $xy+3x+3y+9=0$ is

If $\alpha x^2+2 \gamma x y+\beta y^2=0$ is the equation of a pair of lines passing through the origin and perpendicular to the pair of lines $b h x^2+a b x y+a h y^2=0$ $(a \neq 0, b \neq 0)$,then $\frac{\alpha \beta}{\gamma^2}=$