Answer: last option
Step-by-step explanation:
You need to remember the identity:
[tex]cos\alpha=\frac{adjacent}{hypotenuse}[/tex]
You need to find the cosine of angle P, then, you can identify in the figure that:
[tex]adjacent=PR=21\\hypotenuse=PQ=29\\\alpha=P[/tex]
Therefore, the next step is substitute these values into [tex]cos\alpha=\frac{adjacent}{hypotenuse}[/tex], then you get:
[tex]cos(P)=\frac{21}{29}[/tex]
You can observe that this matches with the last option.
