Pls help me with trig! i’d appreciate it

Answer:
(3√5)/2
Step-by-step explanation:
[tex]Hypotenuse = c =21\\Adjacent=a =6\\\alpha=angle\\Using SOHCAHTOA ,\\Cos \alpha =\frac{adj}{hyp} \\Cos \alpha =\frac{6}{21} \\\alpha = cos^{-1} \frac{6}{21}\\\alpha =73.398\\\\Tan \alpha =\\Tan 73.4\\= 3.354\\=\frac{3\sqrt{5} }{2}[/tex]