Question

sin36sin72sin108sin144

Answer 1

$\sin(36) \times \sin(72) \times \sin(108) \times \sin(144) \\ \cos(180 - 36) \times \cos(180 - 72) \times \sin(108) \times \sin(144) \\ \cos(144) \times \cos(108) \times \sin(108) \times \sin(144) \\ \cos(144) \times \sin(144) \times \cos(108) \times \sin(108) \\ 1 \times 1 \\ 1$
so the answer is 1