Question

1) Find AB

B
A 9 in
Use the Law of
Sines:
SinA
a
(0) 8 in
A
54°
11 in
D 7 in
5 in
SinB
b
12
31 in
SinC
C
Remember

Answer 1

Check the picture below.

`\textit{Law of sines} \\\\ \cfrac{\sin(\measuredangle A)}{a}=\cfrac{\sin(\measuredangle B)}{b}=\cfrac{\sin(\measuredangle C)}{c} \\\\[-0.35em] ~\dotfill\\\\ \cfrac{\sin(54^o)}{31}=\cfrac{\sin(12^o)}{AB}\implies AB\sin(54^o)=31\sin(12^o) \\\\\\ AB=\cfrac{31\sin(12^o)}{\sin(54^o)}\implies AB\approx 8~in`

Make sure your calculator is in Degree mode.