6.1 Laws of Sine

6.1 day 1 Law of Sine.notebook
March 24, 2015
NOTES 6.1
COMPLETED
Solving Oblique Triangles using the LAW OF SINES
6.1 day 1 Law of Sine.notebook
March 24, 2015
Pre Calc 6.1 LAW OF SINES
solvingoblique triangles: triangles that have ________________________
To solve an oblique triangle, you need to know:
USES LAW OF SINES
1. AAS or ASA (2 angles and any side) 2. SSA (2 sides and an angle opposite one of them) USES LAW OF COSINES
3. SSS ( 3 sides)
4. SAS (2 sides and their included angle)
LAW OF SINES
IF Δ ABC HAS SIDES a,b,and c, then
sin A
a
= sin B
b
or
this is also written as
procals
the reci
o
d
o
s
l
a
can
sin B
b
= sin C
c
or
= sin C
a
c
sin A
6.1 day 1 Law of Sine.notebook
March 24, 2015
1. Solve Δ ABC given that a=8, A= 36 , B = 48
C
b=
c=
< C=
you should always show an answer box with all answers together
must
show
optional
must
show
A
B
must
show
optional
must
show
6.1 day 1 Law of Sine.notebook
March 24, 2015
2. Solve Δ ABC given that a=7, b=6, A=26 18 (or 26.3 ) c=
< B=
< C=
SSA or ASS
A This is an example of an ambiguous case because 2 triangles are existing simultaneously. Depending on B
C
which piece you solve for first, second, and third, you would either get a triangle that is acute or a triangle that is obtuse. You may not know when this is occurring because you will only get one of the answers.
must show
must show
optional optional
optional
optional
must must show
show
must show
must show
must show
must show
optional
must show
must show
Note: Answer will be dependent on how original problem is written. If original problem uses degrees & minutes, answer must be in deg & min. If original problem only has degrees, then answer only has degrees.
6.1 day 1 Law of Sine.notebook
March 24, 2015
3. Because of prevailing winds, a tree grew so that it was leaning 6 from the vertical. At a point 30 meters from the tree, the angle of elevation to the top of the tree is 22.5 . Find the height h of the tree.
h
22.5
30 m
6.1 day 1 Law of Sine.notebook
March 24, 2015
a=
<A=
<C=
14
88
62
6.1 day 1 Law of Sine.notebook
March 24, 2015
{
HW
pg 436: 8­20 EVEN
21, 29­34 ALL
Finding Area
of a Triangle