Instantly share code, notes, and snippets. rjlutz/ComputeAngles.java Last active Jun 19, 2017

Math, Characters, Strings (Chapter 4) - examples from Liang Intro to Java Comprehensive 10e
 import java.util.Scanner; public class ComputeAngles { public static void main(String[] args) { Scanner input = new Scanner(System.in); // Prompt the user to enter three points System.out.print("Enter three points: "); double x1 = input.nextDouble(); double y1 = input.nextDouble(); double x2 = input.nextDouble(); double y2 = input.nextDouble(); double x3 = input.nextDouble(); double y3 = input.nextDouble(); // Compute three sides double a = Math.sqrt((x2 - x3) * (x2 - x3) + (y2 - y3) * (y2 - y3)); double b = Math.sqrt((x1 - x3) * (x1 - x3) + (y1 - y3) * (y1 - y3)); double c = Math.sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2)); // Compute three angles double A = Math.toDegrees(Math.acos((a * a - b * b - c * c) / (-2 * b * c))); double B = Math.toDegrees(Math.acos((b * b - a * a - c * c) / (-2 * a * c))); double C = Math.toDegrees(Math.acos((c * c - b * b - a * a) / (-2 * a * b))); // Display results System.out.println("The three angles are " + Math.round(A * 100) / 100.0 + " " + Math.round(B * 100) / 100.0 + " " + Math.round(C * 100) / 100.0); } }