**Q:** What is trigonometry?

**A:** Trigonometry is the study of how
the sides and angles of a triangle are related to each other.

**Q:** WHAT? That’s all?

**A:** Yes, that’s all. It’s all about triangles, and you can’t
get much simpler than that.

**Q:** You mean trigonometry isn’t some big, ugly monster that
makes students turn green, scream, and die?

**A:** No. It’s just triangles.

**Q:** Oh. But isn’t that boring?

**A:** We’ll try to make it a little more fun by letting you
play around with the triangles interactively.

Let’s start. Click on a topic to go to that page. If this is your first visit to these pages, we recommend that you start with the first item in the list.

- Stick and Shadows (part 1)
- Stick and Shadows (part 2)
- Shadows and Triangle
- Measuring the Sides
- sine and cosine
- Going in Circles
- Too Many Numbers
- sine and cosine Do "the Wave"
- Frequency and Amplitude
- Adding Waves
- A Quick Review
- Off on a Tangent
- Surveying the Uses of Trigonometry
- A Few Final Words

This material assumes that you know:

- How to measure angles.
- That a right angle is is 90 degrees.
- The sides of a triangle: the base, the height, and the hypotenuse.

If you aren’t familiar with these concepts, you’ll have to ask your math teacher to assist you with them.