[Golang]Area of a circle

Another exercise on golang, experience in python helps me pick up golang rather quickly.

calculate the area of a circle.

package main

import (
	"fmt"
	"math"
)

func area(radius float64) float64 {
	return math.Pi * radius * radius
}

func main(){
	var r float64
	fmt.Println("Enter radius: ")
	fmt.Scanf("%f", &r)
	a := area(r)
	fmt.Printf("The radius is %f and the area is %f.", r, a)
}