[LAB1-Exercise] Calculate circumference and area of a circle from its diameter

float rad=7; //radius=7
float cir ; //Circumference
float A ; //Area
void setup()
{
   //Calculate
  cir = 2 * PI * rad ;
  A = PI * sq(rad) ;

//Value
  println("Radius =" +rad);

  //Answer
  println("Circumference =" +cir);
  println("Area =" +A);
}