A string of certain length n makes one perfect turn around a cube of side A, starting from corner X and ending at Y (as in the fig). Find the length of the string.
Options:
A .  
√2A
B .  
√17A
C .  
A
D .  
√17(A + 1)
Answer: Option B : B
The string is wrapped equally around the cube 4 times.
So the part ab = A/4. The hypotenuse of the triangle √(A2)+A216The length of the string is four times this hypotenuse.
Submit Solution