Lab1 - Calculate circumference and area of a circle from its diameter

void setup(){
 float d=7;
 float circumference;
 float areaofacircle;
 circumference = PI*d;
 areaofacircle = PI*(d/2)*(d/2);
 println("Diameter is" ,d);
 println("Circumference is" ,circumference);
 println("Area of a circle is" ,areaofacircle);
}