struct Circle {x: f64, y: f64, radius: f64}

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

impl HasArea for Circle {
    fn area(&self) -> f64 {
        std::f64::consts::PI * (self.radius * self.radius)
    }
}


fn main() {
    let c = Circle{x: 12.0, y: 34.0, radius: 56.0};
    println!("Fläche = {}", c.area())
}