Returns

fn main(){
  let (mut radius, mut pi) = (3.0, 3.14);
  let(area, _perimeter) = calculate (
      &mut radius,
      &mut pi
  );
  println!("The area and the perimeter of the circle are: {area} & {\_perimeter}");
}
fn calculate(radius : &mut f64, pi: &mut f64) -> (f64, f64){
  let perimeter = 2.0 * *pi * *radius;
  let area = *pi * *radius * *radius;
  return (area, perimeter);
}