Pythagoras and Trigonometry

Pythagoras and Trigonometry

1. a² + b² = c²

2. a / sin A = b / sin B = c /sin C

   • sin A /a = sin B / b = sin c / C

3. c² = a² + b² - 2abcosC

   • cos A = b² + c² - a² / 2bc

4. Area of triangle = 1/2 ab sinC