OpenStax: Algebra and Trigonometry

Algebra and Trigonometry provides a comprehensive exploration of algebraic principles and meets scope and sequence requirements for a typical introductory algebra and trigonometry course.

Mathalicious: As the World Turns (HS)

In this lesson students use rates, arc length, and trigonometry to determine the speed at which points on the Equator, Tropic of Cancer, and Arctic Circle travel due to the Earth’s rotation.

Khan Academy: High School Geometry
Khan Academy

Learn high school geometry for free—transformations, congruence, similarity, trigonometry, analytic geometry, and more.

Khan Academy: Trigonometry
Khan Academy

Learn trigonometry for free—right triangles, the unit circle, graphs, identities, and more.

Real World Math: Project Based Learning - SketchUp
Real World Math

Google SketchUp software enables students to create 3D models that can be placed in Google Earth. 

NRICH: Tangled Trig Graphs
NRICH (University of Cambridge)

Can you work out the equations of the trig graphs I used to make my pattern?