Solution: Rectangle ARGS

use std::env;
use std::process::exit;

fn main() {
    let args: Vec<String> = env::args().collect();
    if args.len() != 3 {
        println!("Usage {} length width", args[0]);
        exit(1);
    }
    let width: i32 = args[1].parse().expect("Wanted a number");
    let height: i32 = args[2].parse().expect("Wanted a number");

    let area: i32 = width * height;
    let circumference = 2 * (width + height);

    println!("area: {area}");
    println!("circumference: {circumference}");
}

cargo run

Usage target/debug/rectangle-args length width

cargo run  3 4


area: 12
circumference: 14