Respuesta :

Answer:

Step-by-step explanation:

Use the Law of Cosines:

a² = b² + c² - 2ab·cos A

Substituting the given values, we obtain:

a² = (10)² + (7)² - 2(10)(7)·cos 52°

    = 100 + 49 - 140·0.6157

     =      149 - 86.1926

     =    62.81

Taking the square root of both sides yields:

a = 7.925, or (to the nearest degree) 8