package main
import (
   "fmt"
   "math"
)
type Circle struct {
   radius float64
}
func (r *Circle)Area() float64{
   return math.Pi * r.radius * r.radius
}
func (r *Circle)Perimeter() float64{
   return 2 * math.Pi * r.radius
}
func main(){
   var radius float64
   fmt.Printf("Enter radius of the circle: ")
   fmt.Scanf("%f", &radius)
   c := Circle{radius: radius}
   fmt.Printf("Area of the circle is: %.2f\n", c.Area())
   fmt.Printf("Perimeter of the circle is: %.2f\n", c.Perimeter())
}

Enter radius of the circle: 7
Area of the circle is: 153.94
Perimeter of the circle is: 43.98