Day04 perimeter

public class Day04C {
    public static void main(String[] args) {
        double base = 13;
        double height = 10;
        double area;

        area = (base * height) / 2;

        System.out.println("the area of a triangle with ");
        System.out.println("a base of " + base);
        System.out.println("and a height of " + height);
        System.out.println("is " + area);

        double lenght;
        double width;
        double perimeter;
        // make a formula to get the perimiter of a rectangle


        System.out.println("the perimeter of a rectangle with ");
        System.out.println("a length of " + lenght);
        System.out.println("and a width of " + width);
        System.out.println("is " + perimeter);
    }
}