9-3

This week we learned 9-3. It was explaining and how to solve with law of sines. You use this whenever you can’t use SOHCAHTOA to solve the triangle.

Law of sines is used with non-right triangles and only use when you have an angle plus opp leg values you know.


The formula for law of sines:
Sin (angle)/opp leg = Sin (angle 2)/opp leg 2

You cross multiply to solve law of sine.



Ex:
AB=25m
Find AC and BC
1. Draw the triangle.
2. Find AC.
3. Sin 20/AC= Sin 50/25.
4. You get 25 sin (20) =sin (50) x.
5. You divide sin 50 on both sides.
6. You get 11.612m which is AC.
7. Find BC
8. Sin 50/25= Sin 110/BC
9. You get BC Sin 50= 25 Sin 110.
10. Divide Sin 50 on both sides
11. You get 25 Sin 110/ Sin 50
12. You get BC= 30.667m.



Basically if you know your formula and everything 9-3 is really easy but it can be really difficult if you do not know your formula. Know your formula and everything and you should be good and comfortable with 9-3.