Respuesta :

Answer: B. 29 mi (which you typed 29 in)

Step-by-step explanation:

Use law of cosine to solve: a²=b²+c²-2bc·cosA (the corresponding angle)

a²=19²+12²-2×19×12×cos (138)

a²=361+144-456cos(138)

a²=505-456cos(138)

a²=843.874 (rounded)

a=29 mi