9.6 and 9.7 review

9.6 and 9.7 review

Sin52

round to nearest 10th

.8

calculator go in order

phone calc 52 sin =

SinA = .38

round to nearest tenth

22.3

calc use 2nd sin .38

phone calc .38 2nd sin

Area of triangle using SAS

 $\frac{1}{2}bc\sin A$  

Find the area of the triangle

 $\frac{1}{2}\times23\times26\times\sin114$  

solution
273.2

Find angle C

Use triangle sum.

C = 180 - 85 - 29

C = 66

Find side a

Use law of sin

 $\frac{\sin85}{9}=\frac{\sin29}{a}$  

 $a\sin85=9\cdot\sin29$  
 $a=4.4$  

Fill in the Blanks

Multiple Choice

Using Angle A = 29

Using law of sin

Find side b

• $\frac{\sin81}{10}=\frac{\sin70}{b}$

• $\frac{\sin29}{10}=\frac{\sin70}{b}$

• $\frac{\sin70}{10}=\frac{\sin29}{b}$

Find Angle C

Use Law of sin

 $\frac{\sin51}{18}=\frac{\sin C}{17}$  
 $18\sin C=17\sin51$  
 $\sin C=.733$  
 $C=47$  

Multiple Choice

Find angle B

• $\frac{\sin40}{16}=\frac{\sin B}{13}$

• $\frac{\sin40}{13}=\frac{\sin B}{16}$

Use law of cos to find side b.

 $b^2=43^2+45^2-2\times43\times45\times\cos88$  $b^2=3738.9$   
 $b=61.1$  

Multiple Choice

 $a^2=23^2+26^2-2\times23\times26\times\cos114$ 

Is this the right setup to find side a?

• Yes

• NO

Fill in the Blanks

Find angle B.

Use law of Cosine

 $27^2=16^2+23^2-2\cdot16\cdot23\cdot\cos B$  
 $729\ =\ 256+529-736\cos B$  
 $-56=-736\cos B$  
 $.076=\cos B$  
 $B=85.6$  

Fill in the Blanks