A Life Lesson?

Hi there, I just came to notice that there's a very general rule of crossing a road while a lorry is approaching you at a constant speed. Indeed it's quite instinctive and you'll love to prove it.

Here you see the 2D view ( from top ) of a street where a pedestrian is standing at point A. He wants to cross the road but you see, a gigantic lorry BEDC is approaching him at a constant speed $v_1$ . Now, you must advise him to wait, but he's in a hurry and he's desperate. What should he do? i.e. in which direction should he proceed given that he also walks at a constant speed $v_2$ .

Find the value of $\theta$ ( in degrees } [ the angle between his path and the line $AC$ joining him and the opposite corner ( $C$ ) of the lorry ] for which the probability of an accident becomes the least.

Hint: Note that the pedestrian doesn't accurately know the velocity of the lorry.

Takeaway: Never try to cross a road perpendicularly; rather you should first imagine a line joining you and $C$ ( the opposite corner ) and proceed in a direction perpendicular to $AC$ and not perpendicular to the road .