ProgBasics02Simple-Operations-P05TrapeziodArea

import java.util.Scanner;

public class P05TrapeziodArea {
        public static void main(String[] args) {
            Scanner scanner = new Scanner(System.in);

            double b1 = Double.parseDouble(scanner.nextLine());
            double b2 = Double.parseDouble(scanner.nextLine());
            double h = Double.parseDouble(scanner.nextLine());

            double area = (b1+b2) * h / 2;
            System.out.println(area);

        }
    }