初学者帮助超载顾问和方法

I'm writing code for school that requires 3 classes (Main, Airport, Coordinates). Airport calculates the distance between two airports. Originally it was 2 classes (Main, Airport). Where doubles are input by the user in Main class and passed through a distanceCalc method in the Airport class. The Coordinates class is added to hold the Latitude and Longitude values instead, and we have to use overloaded constructors and methods in the Airport class to pass the values through the distanceCalc method. I'm writing code for school that requires 3 cla