Answer:
D. adjacent side; hypotenuse
Step-by-step explanation:
Trigonometric ratios
[tex]\sf \sin(\theta)=\dfrac{O}{H}\quad\cos(\theta)=\dfrac{A}{H}\quad\tan(\theta)=\dfrac{O}{A}[/tex]
where:
- [tex]\theta[/tex] is the angle
- O is the side opposite the angle
- A is the side adjacent the angle
- H is the hypotenuse (the side opposite the right angle)
Therefore, when the cosine trigonometric ratio is used to find a given angle, we take the inverse cosine of the ratio of the adjacent side to the hypotenuse:
[tex]\implies \sf \theta = \cos^{-1}\left(\dfrac{A}{H}\right)[/tex]
