Answer:
cosS = 48/73
Explanation:
cosS is asking for the cosine of angle S.
Cosine is one of the primary trig. ratios, which you can remember using the acronym:
SohCahToa
"o" is opposite.
"h" is hypotenuse.
"a" is adjacent.
Cosine is the "Cah" in the acronym.
cos = a/h
The adjacent side is touching the angle. The hypotenuse is the longest side.
cosS = adjacent/hypotenuse
= QS/RS
= 48/73 This number is already in its lowest terms.