# Sine vs Cosine Continued Exploration in A Right Triangle

- Author:
- Joseph Marutollo, Ben Graber, Megan Mulert

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.
What is the relationship between sine of one triangle related to the cosine of another triangle as you change the angle measure?
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?