From Circle to Sine and Cosine Curves with Angle in Degrees
At the top left the angle varies from to . The distances from the origin to the black and blue points are the values of the sine and cosine, respectively. The cosine is plotted with the sine on the right, using a blue isosceles triangle to project the line segment from horizontal to vertical.
The values of and are shown at the top of the plot.
The lower left circle, which has the same radius as the circle above, shows the right-angled triangle with two sides corresponding to the sine and cosine and its hypotenuse opposite to the right angle.
Inside the lower right circle, the angle is shown in degrees.