Please answer this in two minutes

Answer:
[tex] s = 14.1 [/tex]
Step-by-step explanation:
Given:
<S = 31°
SQ = r = 9
SR = q = 21
s = ?
To find s, use the Law of Cosines:
s² = r² + q² - 2rs*cos(S)
[tex] s^2 = 9^2 + 21^2 - 2*9*21*cos(31) [/tex]
[tex] s^2 = 81 + 441 - 378*0.8572 [/tex]
[tex] s^2 = 522 - 324.02 [/tex]
[tex] s^2 = 197.98 [/tex]
[tex] s = 14.1 [/tex] (nearest tenth)