Option D:
[tex]$\cos60^\circ=\frac{7}{14}[/tex]
Solution:
Given data:
[tex]$\cos -- = \frac{7}{14}[/tex]
Let the unknown degree be x.
To find the degree x:
[tex]$\cos x = \frac{7}{14}[/tex]
Cancel the common factor 7 in the numerator and denominator.
[tex]$\cos x = \frac{1}{2}[/tex]
Using trigonometry basic formula,
we know that [tex]\cos60^\circ = \frac{1}{2}[/tex].
So, x = 60°.
The unknown degree measure is 60°.
[tex]$\cos 60^\circ= \frac{7}{14}[/tex]
Hence option D is the correct answer.