Geometry points in triangle

The problem

Suppose a right triangle is placed in a plane as shown below. The right-angle point is placed at (0, 0), and the other two points are placed at (200, 0), and (0, 100). Write a program that prompts the user to enter a point with x and y-coordinates and determines whether the point is inside the triangle. Here is a java examples run:

Enter a point's x- and y-coordinates: 100.5 25.5
The point is in the triangle

Breaking it down

private static final double SLOPE = -0.5D;

public static void main(String[] strings) {

    Scanner input = new Scanner(System.in);

    System.out.print("Enter a point's x- and y-coordinates: ");
    double x = input.nextDouble();
    double y = input.nextDouble();
    
    input.close();

    double y1 = calculateY1(x, y);

    if ((x > 200.0D) || (x < 0.0D) || (y > 100.0D) || (y < 0.0D)) {
        System.out.println("The point is not in the triangle.");
    } else {

        if ((y1 <= 100.0D)) {
            System.out.println("The point is in the triangle");
        } else {
            System.out.println("The point is not in the triangle.");
        }
    }

}

private static double calculateY1(double x, double y) {
    double y1 = y + -x * SLOPE;
    return y1;
}

Output

Enter a point's x- and y-coordinates: 100.5 50.5
The point is not in the triangle.