Find the equation of the line which is at a distance of 3 units from the origin

To Find:The equation of the line.

Given : $\propto=\frac{5}{12}$ and $p=3$ units.

Since $\tan \alpha=\frac{\text { opp }}{\text { adj }}=\frac{5}{12}$

Using Pythagoras theorem :

hyp $=\sqrt{25+144}=\sqrt{169}=13$ units.

From the figure: $\cos \propto=\frac{\text { adj }}{\text { hyp }}=\frac{12}{13}$ and $\sin \propto=\frac{\text { opp }}{\text { hyp }}=\frac{5}{13}$

Formula used:

equation of the line: $x \cos \alpha+y \sin \propto=p$

$x \times\left(\frac{12}{13}\right)+y \times\left(\frac{5}{13}\right)=5$

Hence, $12 x+5 y=65$ is the required equation of the line.