Answer:
74.2°
Step-by-step explanation:
Given:
m<A = 60°
a = 18 cm
b = 20 cm
Required:
m<ABC = B
Solution:
Apply the sine rule
[tex] \frac{sin(B)}{b} = \frac{sin(A)}{a} [/tex]
Plug in the values
[tex] \frac{sin(B)}{20} = \frac{sin(60)}{18} [/tex]
Multiply both sides by 20
[tex] \frac{sin(B)}{20}*20 = \frac{sin(60)}{18}*20 [/tex]
[tex] sin(B) = \frac{sin(60)*20}{18} [/tex]
[tex] sin(B) = 0.96225 [/tex]
[tex] B = sin^{-1}(0.96225) [/tex]
[tex] B = 74.2 degrees [/tex] (approximated to nearest tenth)
