Respuesta :

Answer:

Option 2

Step-by-step explanation:

Using cosine rule for this triangle

=> [tex]a^2= b^2+c^2-2bc(Cos A)[/tex]

Where b = 2, c = 1 and A = 25

=> [tex]a^2 = 2^2+1^2 -2(2)(1)(Cos 25)[/tex]

=> [tex]a^2 = 4+1 - 4(0.906)[/tex]

=> [tex]a^2 = 5 - 3.6[/tex]

=> [tex]a^2 = 1.4[/tex]

Taking sqrt on both sides

=> a = 1.2