Free forever · Code-first

Learn Trig Math

Trigonometry explained for software developers — every concept pairs math notation with runnable Python and JavaScript so you can use it in graphics, games, and animations.

Always Free: We will never charge a cent.

Your learning path

Six units, sixteen lessons. Work through them in order — each page ends with practice problems and code you can run.

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Unit 1: Foundations

What trig is, degrees vs radians, and SOH-CAH-TOA right-triangle ratios.

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Unit 2: Circles & Triangles

The unit circle, 45-45-90 and 30-60-90 shortcuts, and solving any triangle with the Laws of Sines and Cosines.

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Unit 3: Functions & Identities

Sine/cosine waves, amplitude and period, core identities, and inverse trig with atan2.

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Unit 4: Trig in Code

Capstone recipes — rotations, oscillations, canvas drawing — plus the degrees-vs-radians bug gallery and a live JS playground.

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Unit 5: Games & Graphics

Full builds — a canvas analog clock, a projectile lab, and a mouse-aimed turret game.

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Unit 6: Waves, Sound & Data

Web Audio tones and beats, sine easing for animation, map bearings and GPS distances.

Why learn here?

Built for developers who want to use trig, not just pass a test on it.

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Math + code side by side

Every identity and formula ships with Python (math) and JavaScript (Math) snippets you can run immediately.

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Radians without tears

Degrees-to-radians conversion, angle normalization, and the

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Practice every page

Each lesson ends with hand-computation drills plus small coding tasks like radial menus, sprite rotation, and clock faces.

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KaTeX-rendered formulas

Crisp math typesetting on every page, with unit-circle values and exact radicals (√2/2, √3/2) spelled out, not skipped.

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Graphics-ready capstone

Unit 4 turns theory into game loops — orbits, aiming with atan2, bobbing animations, and screen-coordinate (y-down) pitfalls.

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Always free

No paywall, no account. Sixteen lessons, six units, open for everyone.