Answer:
610.9 km
Explanation:
For the plane that is flying at 520km/h:
520km/h * 45minutes * 1h/60minutes = 390 km
For the plane that is flying at 480km/h:
480km/h * 45minutes * 1h/60minutes= 360 km
This is a SAS triangle which means Side angle Side
the formula for this is: a^2 = b^2 + c^2 − 2bc cosA
for this problem it should be:
a^2= (390^2) +(360^2) - 2(390*360)*cos(115)
a should be approximately 610.9 km