Key takeaway: Trigonometry terms connect angles to lengths, starting with sine, cosine and tangent in right triangles and extending to radians, the unit circle, graphs and identities.
Trigonometry starts with right triangles in Geometry, moves to the unit circle in Algebra 2 and ends with identities and inverse functions in Precalculus. These trigonometry terms follow that path in order, so each word builds on the one before.
Each page shows a triangle, a circle or a wave with the exact values labeled, plus a problem solved with a calculator-ready method.
21 terms on this page, each with a definition, a figure and a worked example.
Trigonometry Terms: the full list
Grade 10 – Geometry
- Angle of Elevation and Depression G-SRT.C.8
- Cosine G-SRT.C.6
- Law of Cosines G-SRT.D.10
- Law of Sines G-SRT.D.10
- Radian G-C.B.5
- Sine G-SRT.C.6
- SOHCAHTOA G-SRT.C.6
- Special Right Triangles G-SRT.C.6
- Tangent (Trigonometric Ratio) G-SRT.C.6
Grade 11 – Algebra 2
- Amplitude F-TF.B.5
- Coterminal Angles F-TF.A.1
- Midline F-TF.B.5
- Period of a Function F-TF.B.5
- Pythagorean Identity F-TF.C.8
- Reference Angle F-TF.A.2
- Unit Circle F-TF.A.2
Grade 12 – Precalculus
- Double-Angle Formulas F-TF.C.9
- Inverse Trigonometric Functions F-TF.B.6
- Phase Shift F-BF.B.3
- Sum and Difference Formulas F-TF.C.9
- Trigonometric Identities F-TF.C.9

