1. Sine Law

2. General and Specific Outcomes
Math 30-3 Geometry
General Outcome
Solve problems by using the sine law and cosine law, excluding the ambiguous case. [CN, PS, V]
Specific outcomes
Identify and describe the use of the sine law and cosine law in construction, industrial, commercial and artistic applications.
Solve a problem, using the sine law or cosine law, when a diagram is given.

3. Recall: When working with right-angle triangles, we can use:
SinA= opposite/hypotenuse
CosA= adjacent/hypotenuse
TanA= opposite/adjacent

4. *
Text *

5. A b c C B a

6. What happens if our triangle is not a right angle triangle
What happens if our triangle is not a right angle triangle? We no longer have a hypotenuse. We need a tool to help us to calculate the different variables of the triangle.

7. A b c C B a

8. A b c C B a Sine law: a b c ------- = ------- = -------
= =
sin A sin B sin C b c C B a

9. A b c C B a Sine law: a b c ------- = ------- = -------
= =
sin A sin B sin C b c C B a

10. A=40
C=63
a=1087m
to find c:
a = c .
sin A Sin C
= c .
sin Sin 63
1087(Sin63) = c
Sin 40
c= m 40 b c 63 B
1087 m

11. We know that there are 180 degrees in every triangle so:
a b c
= =
sin A sin B sin C 40
How can we find b?
We know that there are 180 degrees in every triangle so:
B= = 77 b m 63 B
1087 m

12. A b c C B a Sine law: a b c ------- = ------- = -------
= =
sin A sin B sin C b c C B a

13. find a