Answer:
0°
Step-by-step explanation:
[tex] \because \sin \: 2 \theta = 2 \sin \theta \\ \therefore \: 2\sin \theta \: \cos \theta = 2 \sin \theta \\ \\ \therefore \: \cos \theta = \frac{2 \sin \theta}{2 \sin \theta} \\ \\ \therefore \: \cos \theta = 1 \\ \therefore \: \cos \theta =\cos0 \degree \\ \implies \: \huge \red { \boxed{\theta = 0 \degree}}[/tex]
