C# :: Accept Two Input Parameter And Returns Two Out Values

class Program {
//Accept two input parameter and returns two out value
public static void rect(int len, int width, out int area, out int perimeter) {
area = len * width;
perimeter = 2 * (len + width);

[Code] .....

why is the static keyword required in the method signature for the rect() method. It will not compile if it is absent. why?

the same is true for this example:

class Program {
static void printvalues(params int[] passedin) {
foreach (var printthis in passedin) {
Console.WriteLine(printthis);

[Code] ....

This code won't compile without the static keyword in the printvalues() method signature. why?