The angle between the two lines $y - 2x = 9$ and $x + 2y = -7$ is .....$^o$.

The angle between the straight lines $3x + 4y + 9 = 0$ and $x - 7y - 22 = 0$ is

Find the angle between the lines $y - \sqrt{3}x - 5 = 0$ and $\sqrt{3}y - x + 6 = 0$. (in $^{\circ}$)

Find the equation of the line passing through the point $(2, 3)$ and making an angle of $\frac{\pi}{4}$ with the line $2x + 3y = 5$.

Two straight lines $3x + 4y = 5$ and $4x - 3y = 15$ intersect at the point $A$. The equations of the lines passing through $(1, 2)$ and intersecting the given lines at $B$ and $C$ such that $AB = AC$ are

The acute angle between the lines $x \cos 30^{\circ} + y \sin 30^{\circ} = 3$ and $x \cos 60^{\circ} + y \sin 60^{\circ} = 5$ is (in $^{\circ}$)