在javaFX中绘制简单的90度三角形

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.canvas.Canvas;
import javafx.scene.canvas.GraphicsContext;
import javafx.scene.layout.StackPane;
import javafx.scene.paint.Color;
import javafx.stage.Stage;

public class TriangleDrawing extends Application {

    @Override
    public void start(Stage primaryStage) {
        Canvas canvas = new Canvas(400, 400);
        GraphicsContext gc = canvas.getGraphicsContext2D();

        // 设置三角形的顶点坐标
        double x1 = 200;
        double y1 = 100;
        double x2 = 100;
        double y2 = 300;
        double x3 = 300;
        double y3 = 300;

        // 绘制三角形
        gc.setFill(Color.RED);
        gc.setStroke(Color.BLACK);
        gc.setLineWidth(2);
        gc.beginPath();
        gc.moveTo(x1, y1);
        gc.lineTo(x2, y2);
        gc.lineTo(x3, y3);
        gc.closePath();
        gc.fill();
        gc.stroke();

        StackPane root = new StackPane(canvas);
        Scene scene = new Scene(root, 400, 400);
        primaryStage.setScene(scene);
        primaryStage.setTitle("Triangle Drawing");
        primaryStage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }
}