Solve cos(θ) = -1/2 for 0° ≤ θ < 360°.

We need to find all angles between 0° and 360° for which:
cos(θ) = -1/2

First, determine the reference angle.

We know:
cos(60°) = 1/2

Therefore, the reference angle is 60°.

Cosine is negative in Quadrants II and III.

For Quadrant II:
θ = 180° - 60°
θ = 120°

For Quadrant III:
θ = 180° + 60°
θ = 240°

Check both values:
cos(120°) = -1/2
cos(240°) = -1/2

Both angles lie in the required interval.

Therefore, the solutions are θ = 120° and θ = 240°.