Enter an angle to get sine, cosine and tangent, or a ratio to get the angle back.
Radians = degrees × π ÷ 180. tan θ = sin θ ÷ cos θ. Inverse functions (sin⁻¹, cos⁻¹, tan⁻¹) return the angle.
sin 30° = 0.5, cos 60° = 0.5, tan 45° = 1, and sin⁻¹(0.5) = 30°. 180° = π ≈ 3.1416 rad.