1. Section 6.1 The Law of Sines

2. a triangle that does not contain a right angle.
Oblique Triangle:
a triangle that does not contain a right angle.
An oblique triangle has either three acute angles or two acute angles and one obtuse angle.

3. The Law of Sines
The Law of Sines can be used to solve a triangle in which one side and two angles are known. SAA (a side and two angles are known) or ASA (two angles and the side between them are known).
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4. When to use what? Right Triangles Oblique Triangles
Pythagorean Theorem
Law of Sines
soh-cah-toa
Law of Cosines

5. SAA ASA
430
b=70
200
c=32

6. Find the length of side a Find the length of side c
A=35 C= 79 c= A=25 C= 87 b=14

7. Example

8. Use the Law of Sines to solve,if possible,the triangle or triangles in the ambiguous case.

9. SSA
Ambiguous
a=20”
810
c=12”
BEWARE OF TWO ANSWERS!!!

10. SSA
Ambiguous
a=12”
b=15”
690
BEWARE OF TWO ANSWERS!!!

11. The Area of an Oblique Triangle
Why?

12. Example
b=5”
c=6”

13. Example

14. QUICK POLL
(a)
(b)
(c)
(d)

15. (a)
(b)
(c)
(d)

16. 6.1 Home Work P. 651 Choose odds # 1-7 pick 3 # 9-15 pick 3