Answer: The correct option is
(B) [tex]\dfrac{12}{13}.[/tex]
Step-by-step explanation: We are given to find the value of cos B in the right-angled triangle ABC shown.
From the figure, we can see that
AB = 12 units, BC = 13 units and AC = 5 units.
For the acute angle B, we have
base, b = AB = 12 units
and
hypotenuse, h = BC = 13 units.
Therefore, we get
[tex]\cos \angle B=\dfrac{base}{perpendicular}\\\\\\\Rightarrow \cos \angle B=\dfrac{AB}{BC}\\\\\\\Rightarrow \cos \angle B=\dfrac{12}{13}.[/tex]
Thus, option (B) is correct.
