Prove that sin(2α) + sin(2θ) + sin(2pi- 2α-2θ)= 4sin(α)sin(θ)sin(pi-α-θ)

Question

This was a question from my homework that I can't do at all!

Answer 1

For starters sin2a-sin2a=0.

By looking at=4sina*(-sina)=3sina≠0. It doesn't work.

I substituted a=12; θ=24. I got .238=-183