Respuesta :

ricchad

Answer:

BC = 13.4

Step-by-step explanation:

its a law of cosines S-A-S

a² = b² + c² - 2bc cosA

a² = 12.6² + 4.6² - ( 2 * 12.6 * 4.6 * cos 90 )

a² = 179.92

a = sqrt (179.92)

a = 13.4