Given:
- Side of the square track = 2m
- Time taken to complete one round of the track = 40 sec

To find:
- Displacement at the end of 3 minutes

Solution:

Step 1: Calculate the distance covered in one round
- The distance covered in one round of the square track is equal to the perimeter of the square.
- The perimeter of a square is given by the formula P = 4s, where s is the length of one side of the square.
- In this case, the length of one side of the square is 2m.
- Therefore, the distance covered in one round is 4 * 2 = 8m.

Step 2: Calculate the number of rounds completed in 3 minutes
- We know that 1 minute = 60 seconds.
- Therefore, 3 minutes = 3 * 60 = 180 seconds.
- The time taken to complete one round is given as 40 seconds.
- Therefore, the number of rounds completed in 3 minutes is 180 / 40 = 4.5 rounds.

Step 3: Calculate the total distance covered in 3 minutes
- The total distance covered in 3 minutes is equal to the distance covered in one round multiplied by the number of rounds completed.
- In this case, the distance covered in one round is 8m and the number of rounds completed is 4.5.
- Therefore, the total distance covered in 3 minutes is 8 * 4.5 = 36m.

Step 4: Calculate the displacement at the end of 3 minutes
- Displacement is a vector quantity that represents the change in position of an object.
- It is the shortest distance between the initial and final positions, along with the direction.
- In this case, the toy cyclist completes one round of the square track, which means the initial and final positions are the same.
- Therefore, the displacement at the end of 3 minutes is 0m.

Answer:
- The displacement at the end of 3 minutes is 0m.