Mod 2: trigonometry

• Tan = sine/cosine
• Cosec: 1/sin or hypotenuse/opposite

  Secant: 1/cos or hypotenuse/adjacent

  Cotan: 1/tan or adjacent/hypotenuse
• Sin: opposite/hypotenuse

  Cos: adjacent/hypotenuse

  Tan: opposite/adjacent
• Ambiguous case in the sine rule: if the sum of the two angles > 180°, then, there is no ambiguious case, simply put in the answer in the calculator. If the sum of two angles < 180°, then, include the obtuse angle as well, which can be found through 180-theta
• For sine rule: a° + b° > 180°, one sol

  a° + b° < 180°, two sol