Topic description
Given the radius of a circle, find the area and perimeter of the circle .
enter
The input has only one line and only one integer, which is the radius of the circle .
output
The output has only two lines, one for area and one for perimeter. (with two decimal places) .
sample input
1
Sample output
3.14 6.28
program
1.#include<bits/stdc++.h>
2.using namespace std;
3.int main()
4. {
5. double a,b=0,c=0;
6. cin>>a;
7. b=a*a*3.14;
8. c=a*2*3.14;
9. cout<<fixed<<setprecision(2)<<b<<' '<<c;
10. return 0;
11.}