Respuesta :

When angle opposite to the unknown sides and other two sides are given then we use law of cosines

Law of cosine

[tex] c^2 = a^2 + b^2 - 2ab cos(c) [/tex]

From the given diagram

[tex] AB^2 = CB^2 + AC^2 - 2(CB)(AC) cos( c) [/tex]

CB = 108

AC= 55

Angle c= 59

[tex] AB^2 = 108^2 + 55^2 - 2(108)(55) cos( 59 ) [/tex]

[tex] AB^2 = 8570.34767 [/tex]

Take square root on both sides

AB = 92.6 m

To find out angle B we use sine law

[tex] \frac{sin(a)}{a} = \frac{sin b}{b} = \frac{sin c}{c} [/tex]

[tex] \frac{sin b}{b} = \frac{sin c}{c} [/tex]

From the figure

[tex] \frac{sin B}{AC} = \frac{sin C}{AB} [/tex]

[tex] \frac{sin B}{55} = \frac{sin 59}{92.6} [/tex]

sin(B) = 0.50916647

B = [tex] sin^{-1} [/tex](0.50916647)

Angle B= 30.61 degrees