1. Create a circle [icon]/images/ggb/toolbar/mode_circle2.png[/icon]with radius 1 centered on the origin (you should have two points A(0,0) and B(1,0)).[br]2. Create your [b]initial ray[/b] by constructing a vector [icon]/images/ggb/toolbar/mode_vector.png[/icon]from A to B. Right click on the vector, and change it's label to "Initial".[br]3. Create a slider using the [icon]/images/ggb/toolbar/mode_slider.png[/icon]slider tool, and choose "angle". The label on your slider should read "[math]\alpha[/math]=45".[br]4. Now create an angle to use the value from your slider. Use the "angle with given size" [icon]/images/ggb/toolbar/mode_anglefixed.png[/icon] tool. Click on B, then A, then the definition will pop up. Change 45° to [math]\alpha[/math]. This should create an angle that is controlled by your slider, and a new point B' on your circle. Test your slider to see the angle change.[br]5. Create a new vector from A to B' called "Terminal".[br]6. Drop a perpendicular line [icon]/images/ggb/toolbar/mode_orthogonal.png[/icon]from B' to the x-axis. Mark the intersection [icon]/images/ggb/toolbar/mode_intersect.png[/icon] of this line with a point (should be point C).[br]7. Draw r[b]eference triangle[/b] AB'C using the polygon tool[icon]/images/ggb/toolbar/mode_polygon.png[/icon]. Remove the labels for sides, and show the label for the shape. Change its name to "Reference[math]\Delta[/math]".

By now, your unit circle should look something like the one below. See if you can figure out how to display the values of sine and cosine like I did below.