C

Let $ABC$ be a triangle (see the picture). Determine the angle $\phi$ between the height $v_c$ and the median $t_c$. Give the angle rounded to minutes.

Find general form equations of all the lines passing through the point $M=[-2;4]$ at the distance of $2$ from the origin $O$ (see the picture).

Let $2x-3y+6=0$ be the equation of the line $p$ and let $M$ be the point $[5;3]$. Find equations of all lines passing through $M$ and intersecting $p$ at an angle of ${45}^{\circ }$ (see the picture).

Let $p$ and $q$ be intersecting lines with the equations $y=\frac{\sqrt{3}}{3}x$ and $x=0$ respectively. Find equations of lines $o_1$ and $o_2$ that are lines of symmetry of the angles contained between $p$ and $q$ (see the picture).