Trigonometry
Trigonometry starts with right triangles, but it quickly expands into the unit circle, periodic graphs, and real-world motion. This path moves from core ratios to interactive exploration, so you can see how sine, cosine, and tangent behave as both measurements and functions. Along the way, you’ll connect identities, angles, and graphs into one coherent picture.
Learning Path
Trigonometry Ratios & Unit Circle
Get the essential definitions, key angle values, and the link between triangle ratios and the unit circle.
Open →Unit Circle Explorer
Move around the circle to see how angle measure, coordinates, and trig values change together.
Open →Trigonometric & Polar Functions Lab
Investigate how trig functions graph over time and how they connect to polar form and periodic behavior.
Open →Trig essentials to keep handy
Use this as a quick checkpoint while you practice and graph.
- SOHCAHTOA helps you remember sine, cosine, and tangent in right triangles.
- The unit circle links angle measure to coordinates and signs in each quadrant.
- Trig identities let you rewrite expressions and simplify problems.
More Resources
Tools
Labs
Worksheets
Cheat Sheets
Infographics
Explainers
Common Questions
What is trigonometry used for?
Trigonometry is used to measure angles and lengths in triangles, model periodic motion, and describe patterns in waves, rotation, and oscillation.
Why is the unit circle so important?
The unit circle connects angles to x- and y-coordinates, which makes it easier to understand trig values, signs in each quadrant, and the graphs of sine and cosine.