struct Triangle {
    b: f64,
    h: f64,
}

struct Rectangle {
    l1: f64,
    l2: f64,
}

trait Figure {
    fn area(&self) -> f64;
}

impl Figure for Triangle {
    fn area(&self) -> f64 {
        self.b * self.h / 2.0
    }
}
impl Figure for Rectangle {
    fn area(&self) -> f64 {
        self.l1 * self.l2
    }
}

fn print_area(f: &dyn Figure) {
//fn print_area<T: Figure>(f: &T) {
    println!("The area of this figure is {}", f.area())
}

fn figure_id(v: i32) -> i32 {
  v / 2
}

fn main() {
    let f1 = Triangle{b: 5.0, h: 8.0};
    let f2 = Rectangle{l1: 4.0, l2: 6.0};
    let n;
    let f;

    n = figure_id(5);

    if n == 1 {
        f = &f1 as &dyn Figure;
    } else {
        f = &f2 as &dyn Figure;
    }
    print_area(f)
}