Question

The point (12, 5) is on the terminal side of an angle θ. What is cos θ ?

Answer 1

\(\large \begin{array}{ccllll}
(&12&,&5)\\
&\uparrow &&\uparrow \\
&x&&y
\end{array}\) thus so... what's the hypotenuse?
notice is a right triangle, so you can use the pythagorean theorem to get that

keep in mind your SOH CAH TOA ,thus \(\bf cos(\theta)=\cfrac{adjacent\ side}{hypotenuse}\)