## Unit circle animation

The angle *θ* is shown in grey.

The circle above has radius=1, so the *horizontal* and *vertical* coordinates of the black point correspond to cos(*θ*) and sin(*θ*).

cos(*θ*) is measured (in blue) along the horizontal axis and varies from -1 to 1.

sin(*θ*) is measured (in red) along the vertical axis and varies from -1 to 1.