ShippingContainer.java
package shapes;

import java.util.Scanner;

public class ShippingContainer {
    public static void main(String[]args){
        Scanner c = new Scanner(System.in);
        System.out.print("please enter the width, length and height: ");
        double width = c.nextDouble();
        double length = c.nextDouble();
        double height = c.nextDouble();
        System.out.println("This Container is "+width +" wide, " +length+" deep and " + height +" high");
        SRectangle face = new SRectangle(length, width);
        double Kh = face.diagonal();
        SRectangle key = new SRectangle(Kh ,height);
        double distance = key.diagonal();
        System.out.println("The longest distance of the container is: " + distance);
    }
}
    

Demo

please enter the width, length and height: 32 45 67 This Container is 32.0 wide, 45.0 deep and 67.0 high The longest distance of the container is: 86.82165628459296 Process finished with exit code 0