Lab 1 : Calculate circumference and area of a circle

void setup() {
  int dia;
  float area;
  int rad;
  float cir;
  size(200, 200);
  //setting variable
  dia=50;                 //diameter
  //calculate
  rad=dia/2;
  area=3.14*rad*rad;
  cir=3.14*dia;
  //result
  println("Diameter : "+dia);
  println("Area : "+area);
  println("Circumference : "+cir);
}