Because of the properties of right triangles, the sine and cosine of complementary angles are related in a special way. Use the applet below to explore the relationship between sine and cosine.
a. What is the relationship between angle A and angle C? Is this always true, regardless of the value of angle A? b. How does the sine of angle A compare to the cosine of angle C? Does this relationship remain the same when angle A changes in measurement? c. How does the cosine of angle A compare to the sine of angle C? Does this relationship remain the same when angle A changes in measurement? d. What conclusions can you draw from this? Why do you think this is true? e. As angle A increases, what happens to the value of sine A? f. As angle A increases, what happens to the value of cosine A?