Answer:
B = 34.2°
C = 105.8°
c = 12.0 units
Step-by-step Explanation:
Given:
A = 40°
a = 8
b = 7
Required:
Find B, C, and c.
SOLUTION:
Using the Law of Sines, find <B:
[tex] \frac{sin(A)}{a} = \frac{sin(B)}{b} [/tex]
[tex] \frac{sin(40)}{8} = \frac{sin(B)}{7} [/tex]
Multiply both sides by 7
[tex] \frac{sin(40)}{8}*7 = \frac{sin(B)}{7}*7 [/tex]
[tex] \frac{sin(40)*7}{8} = sin(B) [/tex]
[tex] 0.5624 = sin(B) [/tex]
[tex] B = sin^{-1}(0.5624) [/tex]
[tex] B = 34.2 [/tex] (to nearest tenth).
Find <C:
C = 180 - (34.2+40°) (sum of angles in a triangle)
C = 180 - 74.2 = 105.8°
Using the Law of Sines, find c.
[tex] \frac{c}{sin(C)} = \frac{b}{sin(B)} [/tex]
[tex]\frac{c}{sin(105.8)} = \frac{7}{sin(34.2)}[/tex]
Multiply both sides by sin(105.8)
[tex]\frac{c}{sin(105.8)}*sin(105.8) = \frac{7}{sin(34.2)}*sin(105.8)[/tex]
[tex] c = \frac{7*sin(105.8)}{sin(34.2)} [/tex]
[tex] c = 12.0 [/tex]
