Lab 2 : Calculate circumference and area of a circle (use function)

void setup() {
 size(400,200);
 background(255);

   float r=10;

  textSize(15);
  fill(0);
  text("Value of a Area = "+area(r)+" cm*cm",40,40);
  text("Value of a Circumference = "+circum(r)+" cm.",40,80);

}

///// calculate area of circle/////

 float area(float r){

   float area;
   area = PI*r*r;
   return area;

}

/////calculate circum of circle/////

  float circum(float r){

   float circum;
   circum = TWO_PI*r;
   return circum;

}