2021 AMC 12D Question 13

Let $c = \dfrac{2\pi}{11}.$ What is the value of $$
\small \dfrac{\sin 3c \cdot \sin 6c \cdot \sin 9c \cdot \sin 12c \cdot \sin 15c}{\sin c \cdot \sin 2c \cdot \sin 3c \cdot \sin 4c \cdot \sin 5c}?
$$