Toolkit for Ex. 12.4

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