Respuesta :

carlosego
For this case what you have to take into account is the following trigonometric relationship:
 TanB = b / a
 We clear the value of b:
 b = a * TanB
 Substituting the values we have:
 b = 10 * Tan (60)
 b = 17.32 m
 Answer:
 b = 17.32 m
 option a.