Trigonometry Circle

Interactive simulation — adjust parameters and watch the visualization update in real time.

How it works

On the unit circle, cos θ is the x-coordinate and sin θ is the y-coordinate of the point at angle θ from the positive x-axis. The diagram shows a circle of radius R in pixels; ratios match the unit circle.

Key equations

cos θ = x,   sin θ = y,   tan θ = sin θ / cos θ