Answer:
70 m
Step-by-step explanation:
AB makes a 30-60-90 triangle with the wall.
AC makes a 45-45-90 triangle with the wall.
In a 30-60-90 triangle, the short leg (opposite of the 30° angle) is half the hypotenuse.
In a 45-45-90 triangle, the legs are the same length.
So the distance between the left wall and the laser is 60/2 = 30 m.
The distance between the right wall and the laser is 40 m.
The total distance is therefore 70 m.
Anywhere from 7 - 13 hours
