Beautiful Trigonometry

See how trigonometry works. Move an angle. Watch a triangle change. Explore the unit circle. Beautiful Trigonometry turns abstract formulas into interactive pictures you can understand. LEARN BY EXPLORING Adjust sliders and see how angles, sides, values and graphs respond instantly. Follow the connection between geometry and the formulas you learn at school. FIVE COMPLETE LESSONS, FREE • Acute Angle Trigonometry: explore sine, cosine, tangent and cotangent in a right triangle. • Full Circle Trigonometry: see values, coordinates and signs across 360°. • Triangle Area with Sine: discover how two sides and an angle determine area. • Law of Cosines: calculate a missing side and connect the rule to Pythagoras. • Trigonometric Identity: understand sin² α + cos² α = 1 using a triangle and the unit circle. GO FURTHER WITH PRO • Explore and compare graphs of sine, cosine, tangent, cotangent, secant and cosecant. • Change function parameters and see how graphs transform. • Unlock six advanced categories in the trigonometric formula library. • Reveal the Same Area Pair visual helper in the triangle area lesson. Core relationships and Pythagorean identities remain free in the formula library. You can preview premium content before unlocking it. ONE PURCHASE. NO SUBSCRIPTION. Trigonometry Pro is a one-time in-app purchase that unlocks all Pro features in this app. Made for high-school students discovering trigonometry, teachers explaining it visually, and curious learners revisiting the basics. Explore an angle. Discover the connection. Make sense of trigonometry.