Having a little trouble with this one Painting a wall import

Having a little trouble with this one!

Painting a wall

import java.util.Scanner;
import java.lang.Math; // Note: Needed for math functions in part (3)

public class PaintEstimator {
public static void main(String[] args) {
Scanner scnr = new Scanner(System.in);
double wallHeight = 0.0;
double wallWidth = 0.0;
double wallArea = 0.0;
  
System.out.println(\"Enter wall height (feet): \");
wallHeight = scnr.nextDouble();
  
System.out.println(\"Enter wall width (feet): \");
wallWidth = scnr.nextDouble();
  
  
wallArea = wallWidth * wallHeight;

Solution

import java.util.Scanner;
import java.lang.Math; // Note: Needed for math functions in part (3)

public class PaintEstimator {
   public static void main(String[] args) {
       Scanner scnr = new Scanner(System.in);
       double wallHeight = 0.0;
       double wallWidth = 0.0;
       double wallArea = 0.0;

       System.out.print(\"Enter wall height (feet): \");
       wallHeight = scnr.nextDouble();

       System.out.print(\"Enter wall width (feet): \");
       wallWidth = scnr.nextDouble();

       wallArea = wallWidth * wallHeight;
       double gallonsPaint = calculateGallonsPaint(wallArea);
       int noOfCans = cansNeeded(gallonsPaint);

       System.out.println(\"Wall area: \" + wallArea + \" square feet\");
       System.out.println(\"Paint needed: \" + gallonsPaint + \" gallons\");
       System.out.println(\"Cans needed: \" + noOfCans + \" can(s)\");

   }

   /**
   * provide formula for calculate
   *
   * @param surfaceArea
   * @return
   */
   public static double calculateGallonsPaint(double surfaceArea) {
       return 0;
   }

   /**
   * provide formula for calculate
   *
   * @param gallonsPaint
   * @return
   */
   public static int cansNeeded(double gallonsPaint) {
       return 0;
   }

}

OUTPUT:

Enter wall height (feet): 12
Enter wall width (feet): 15
Wall area: 180.0 square feet
Paint needed: 0.0 gallons
Cans needed: 0 can(s)

NOTE: please comment formulas or logic to calculate above things