How to fill a triangle using Graphics class (Java)

Question

My goal is to be able to draw/fill in a triangle using the Graphics class. I was able to fill in/draw a rectangle & a circle but when I try to compile my code I get the error below.

I understand that the fill polygon method takes in type arrays but I don't know what other method to use other then .fillPologyon that takes in the parameters I want.

Is there another method that I didn't try? Is there a way to convert my width & height for my rttriangle while not messing up the code for drawing a rectangle.

DrawArea.java:62: error: no suitable method found for fillPolygon(int,int,int,int)
                    g.fillPolygon(100, 100, width, height);
                     ^
method Graphics.fillPolygon(int[],int[],int) is not applicable
  (actual and formal argument lists differ in length)
method Graphics.fillPolygon(Polygon) is not applicable
  (actual and formal argument lists differ in length)
  1 error

import java.awt.*;
import javax.swing.*;
public class DrawArea extends JComponent {
private int radius;
private int width; // base for rt trig
private int height;
//private int [] w = new int[]
//private int [] h = new int[];
private String shape;

/**
 * constructor for circle
 * @param shape string "circle"
 * @param r the radius the user entered
 */
public DrawArea(String shape, int r){
    this.shape = shape;
    radius = r;
}
/**
 * constructor for rectangle and right triangle
 * @param shape either the string "rectanlge" or "triangle"
 * @param w - either the width or the base
 * @param h - height of rect or tri
 */
public DrawArea(String shape, int w, int h){
    this.shape = shape;
    width = w;
    height = h;


}
/**
 * paint method that draws the selected shape
 */
public void paintComponent(Graphics g){ // Graphic g is and object allows you to set color to green
    removeAll();
    if(shape.equals("circle")){
        //Set color to green
        g.setColor(Color.green);
        // 100 pixels down 100 pixels over
        //How wide and how tall = radius *2 = diamter
        //There broth width and height
        g.fillOval(100, 100, radius * 2, radius * 2);   
    }else if(shape.equals("rectangle")){
        g.setColor(Color.green);
        g.fillRect(100, 100, width, height);   //change  **************************************
    //}else{

    }else if(shape.equals("rtTriangle")){
        g.setColor(Color.green);
        g.fillPolygon(100, 100, width, height);
    }
  }
}

Answer 1

You may want to define your triangle as a Polygon , and use fillPolygon(Polygon) e.g:

Polygon triangle = new Polygon();
triangle.addPoint(40, 55);
triangle.addPoint(60, 55);
triangle.addPoint(50, 35);

g.setColor(Color.green);
g.fillPolygon(triangle);

Now just use your width and height variables, to define the three points of the triangle as you need.

Here is an example of the points you could use :

triangle.addPoint(0, height); // bottom-left angle
triangle.addPoint(width, height); // bottom-right angle
triangle.addPoint(width / 2, 0); // top angle