# Java 程序：計算三角面積 > 原文： [https://beginnersbook.com/2014/01/java-program-to-calculate-area-of-triangle/](https://beginnersbook.com/2014/01/java-program-to-calculate-area-of-triangle/) 在這里，我們將看到如何計算三角形的面積。我們將看到以下兩個程序： 1）程序 1：提示用戶輸入三角形的基本寬度和高度。 2）程序 2：無用戶交互：程序本身指定了寬度和高度。 **計劃 1：** ```java /** * @author: BeginnersBook.com * @description: Program to Calculate area of Triangle in Java * with user interaction. Program will prompt user to enter the * base width and height of the triangle. */ import java.util.Scanner; class AreaTriangleDemo { public static void main(String args[]) { Scanner scanner = new Scanner(System.in); System.out.println("Enter the width of the Triangle:"); double base = scanner.nextDouble(); System.out.println("Enter the height of the Triangle:"); double height = scanner.nextDouble(); //Area = (width*height)/2 double area = (base* height)/2; System.out.println("Area of Triangle is: " + area); } } ``` 輸出： ```java Enter the width of the Triangle: 2 Enter the height of the Triangle: 2 Area of Triangle is: 2.0 ``` **計劃 2：** ```java /** * @author: BeginnersBook.com * @description: Program to Calculate area of Triangle * with no user interaction. */ class AreaTriangleDemo2 { public static void main(String args[]) { double base = 20.0; double height = 110.5; double area = (base* height)/2; System.out.println("Area of Triangle is: " + area); } } ``` 輸出： ```java Area of Triangle is: 1105.0 ```