Lesson#1 Exercise 12.4 Toolkit for Exercise 12.4 How to solve a triangle? To solve a triangle, we can use following formulas: (1) ++=180° Don’t use Law of Sines for finding angle, it will go wrong if angle will be obtuse. /(sin )=/(sin )=/(sin ) /(sin )=/(sin ) /(sin )=/(sin ) /(sin )=/(sin ) Math.Ex.12.4, Part1-12.4 (3) Law of Cosines Law of Cosines reduces to Pythagoras theorem if involved angle will be 90°. (4) Law of Tangents (i) (−)/(+)=(tan (−)/2)/(tan (+)/2) (ii) (−)/(+)=(tan (−)/2)/(tan (+)/2) (iii) (−)/(+)=(tan (−)/2)/(tan (+)/2) Application of Trigonometry Chapter No 12 Mathematics part 1
