(a) Demonstrate that the equation \(\sin 2\theta + \cos 2\theta = 2 \sin^2 \theta\) can be rewritten as \(\cos^2 \theta + 2 \sin \theta \cos \theta - 3 \sin^2 \theta = 0\).

(b) Solve the equation \(\sin 2\theta + \cos 2\theta = 2 \sin^2 \theta\) for \(0^\circ < \theta < 180^\circ\).