Use the slider and point D to figure out how sin, cos, and tan are related to a, b, and c and the size of the triangle. You may want to make a table to keep track of your observations. This applet was created by Jennifer Silverman for Geometry21

Make sure to work with the slider first exploring its effect on the three trigonometric values. After you have recorded your observations about the impact of the angle changes, explore what happens when D is moved. What do you notice? How can you explain what is the same or what is different under these conditions?