How did my teacher get 6 meters of fence?

Without the original problem, it's impossible to know exactly how your teacher arrived at 6 meters of fence. However, this value would typically be the result of calculating the perimeter of an area to be fenced or the length of a specific side of a structure.

For example:

• If the fence was for a square garden with sides of 1.5 meters, the perimeter would be $4 \times 1.5\ \text{m} = 6\ \text{m}$.
• If the fence was for a rectangular garden that was 2 meters wide and 1 meter long, but only three sides needed fencing (e.g., one side was a wall), the length could be $2\ \text{m} + 2\ \text{m} + 2\ \text{m} = 6\ \text{m}$ (if it was two sides of 2m and one side of 2m, or similar combinations).
• If it was simply the length of one side of a larger area, that side could be 6 meters long.

To understand the exact calculation, you would need to refer to the specific problem your teacher presented.