Unit Circle Directions: Default Functions: Refresh Button: To reset the applet, click the Refresh Button at the top-right corner. Zoom In/Out: Using your scroll wheel, you can zoom in and zoom out of the applets visible area. The screen tends to re-center wherever the mouse cursor is located. Move: Hold the Shift key and then click and hold your primary mouse button to pan around the visible area of the applet. Movable Objects: Checkboxes: To show or hide the corresponding divisions of the unit circle and also to reveal an interesting pattern to build the unit circle.. Sliders: α and δ: Click and drag the point to view the angle increments in a counter-clockwise or clockwise direction.