Solution.java

import java.util.Scanner;

public class Solution {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        String kelas = scanner.nextLine();
        String nama = scanner.nextLine();

        System.out.println("Nama : " + nama);
        System.out.println("Kelas : " + kelas);
        System.out.println();

        int pilihanBangunDatar = Integer.parseInt(scanner.nextLine());
        
        if (pilihanBangunDatar == 1) {
            int panjang = Integer.parseInt(scanner.nextLine());
            System.out.println("Persegi");
            
            int luas = panjang * panjang;
            System.out.println(luas);
        } else if (pilihanBangunDatar == 2) {
            int alas = Integer.parseInt(scanner.nextLine());
            int tinggi = Integer.parseInt(scanner.nextLine());
            System.out.println("Segitiga");

            int luas = alas * tinggi / 2;
            System.out.println(luas);
        } else if (pilihanBangunDatar == 3) {
            int jariJari = Integer.parseInt(scanner.nextLine());
            System.out.println("Lingkaran");

            double luas = jariJari * jariJari * 22 / 7;
            System.out.println(luas);
        } else {
            System.out.println("Input Anda tidak sesuai");
        }
    }
}