The lawyer: "Did you actually see the accident?"
The witness: "Yes, sir."
The lawyer: "How far away were you when the accident happened?"
The witness: "Thirty-one feet, six and one quarter inches."
The lawyer (thinking he'd trap the witness): "Well, sir, will you tell the jury how you knew it was exactly that distance?"
The witness: "Because when the accident happened I took out a tape and measured it. I knew some stupid lawyer would ask me that question."