# Math Insight

### Applet: Polar coordinates

When you change the values of the polar coordinates $r$ and $\theta$ by dragging the red points on the sliders, the blue point moves to the corresponding position $(x,y)$ in Cartesian coordinates. Alternatively, you can move the blue point in the Cartesian plane directly with the mouse and observe how the polar coordinates on the sliders change. The coordinate $r$ is the length of the line segment from the point $(x,y)$ to the origin and the coordinate $\theta$ is the angle between the line segment and the positive $x$-axis.

Applet file: polar_coordinates.ggb