int LED = 13;
int buzzer = 11;
int t=2;
int e=3;

void setup() {
  // put your setup code here, to run once:
pinMode(LED,OUTPUT);
pinMode(buzzer,OUTPUT);
Serial.begin(9600);
pinMode(2,OUTPUT);
pinMode(3,INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(LED,HIGH);
  delay(1000);
  digitalWrite(LED,LOW);
  delay(1000);
  tone(buzzer,450);
  delay(500);
  noTone(buzzer);
  delay(500);
  digitalWrite(t,LOW);
  delay(100);
  digitalWrite(t,HIGH);
  delayMicroseconds(10);
  digitalWrite(t,LOW);
  float dur=pulseIn(e,HIGH);
  float dis=(dur* 0.0343)/2;
  Serial.print("Distance:");
  Serial.print(dis);
  Serial.print("cm");
    }