Respuesta :

use cosine rule:-
b^2 = 41^2 + 20^2 - 2*20*41*cos 36

       =   754.21

b =  27.5 

you can now find angle A using the sine rule

27.5 / sin 36  = 41 / sin A

sin A  =   0.87633

< A =  61.2 degrees  

Answer:

b= 27.46

A= 61 degree

C= 83 degree

Step-by-step explanation:

Solve the triangle. B=36 a=41 c=20

Apply cosine rule to find the side length B

[tex]b^2= a^2 +c^2-2acsin(A)[/tex]

[tex]b^2 = 41^2 + 20^2 - 2 \cdot 20 \cdot 41 \cdot cos 36[/tex]

Take square root on both sides

so b=27.46292

b= 27.46

Now use sine rule to find the angles A  and C

[tex]\frac{Sin A}{a} = \frac{Sin B}{b}[/tex]

[tex]\frac{Sin A}{41} = \frac{Sin 36}{27.46}[/tex]

Cross multiply it

[tex]27.46 sin(A)= 41 sin(36)[/tex]

[tex]Sin(A) = \frac{41 Sin 36}{27.46}[/tex]

A= [tex]sin^{-1}(\frac{41 Sin 36}{27.46})[/tex]

A= 61 degree

Angle A + angle B + angle C= 180

[tex]61+36 + angle C= 180[/tex]

Angle C= 83 degree