The angle between the line $x+y=3$ and the line joining the points $(1,1)$ and $(-3,4)$ is

If $S_1$ and $S_2$ are two straight lines such that the reflection of $S_1$ in $S_2$ and the reflection of $S_2$ in $S_1$ coincide,the angle between $S_1$ and $S_2$ is equal to?

If the straight lines $2x + 3y - 3 = 0$ and $x + ky + 7 = 0$ are perpendicular,then the value of $k$ is:

The acute angle between two straight lines passing through the point $M(-6, -8)$ and the points in which the line segment $2x + y + 10 = 0$ enclosed between the coordinate axes is divided in the ratio $1 : 2 : 2$ in the direction from the point of its intersection with the $x$-axis to the point of intersection with the $y$-axis is:

Find the equation of the lines passing through the origin and making an angle of $\tan^{-1} m$ with the line $y = mx + c$.

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