The Math Meridian
Back to Trigonometry

Radians and the unit circle

Questions at easy, medium and hard levels. Pick a level and get a fresh set every time, with instant feedback.

Useful for: IB Math AA SL & HL IB Math AI HL AP® Precalculus

Learn it π radians = 180°. A point on the unit circle at angle θ is (cos θ, sin θ). Arc length s = rθ and sector area A = ½r²θ, with θ in radians.

Example: Point on the unit circle at θ = 2π/3?

  1. 2π/3 = 120°: cos 120° = −1/2, sin 120° = √3/2.
  2. (−1/2, √3/2).

Loading questions…