rotate slowly!

i want rotate an object when i press a key once(getkeydown) for 30 degree.also i want to see rotation(slow rotation).how?

To change the speed you need to multiply the vector you want to rotate around by a speed variable.
Check if the y rotation is greater than or equal to the target angle. If it’s not carry on rotating, if it is then stop rotating.

public float speed = 10;
public float angle = 30;
private bool rotating = false;

void Update ()
	if(Input.GetKeyDown(KeyCode.Space) && !rotating) rotating = true;
	if(rotating && transform.eulerAngles.y <= angle)
		transform.Rotate(Vector3.up * (speed * Time.deltaTime));
	else if (rotating) rotating = false;