Answer:
D
Step-by-step explanation:
[tex] \sin(60) = \frac{ \frac{5 \sqrt{3} }{2} }{a} \\ a = \frac{ \frac{5 \sqrt{3} }{2} }{ \sin(60) } = 5 \\ \cos(60) = \frac{b}{5} \\ b = 2.5 = \frac{5}{2} [/tex]
