Question 45536
Think of this as a right triangle.
The crossing is the point at which the right angle is located.
Crossing to car is a leg, and from the crossing to the train is the other leg.
Leg: 30
Leg: a
Hypotenuse: 50
{{{c^2 = a^2 + b^2}}}
{{{2500 = a^2 + 900}}}
{{{1600 = a^2}}}
{{{40 = a}}}
40 meters from the crossing