Answer: 25m²
Explanation:
To find out which field will yield the most vegetables, we need to calculate the area of each field. The formula for the area of a rectangle is:
Area = length x width
Field 1:
Length = 7m (20m of fencing - 3m of width on each side)
Width = 3m
Area = 7m x 3m = 21m²
Field 2:
Length = 6m (20m of fencing - 4m of width on each side)
Width = 4m
Area = 6m x 4m = 24m²
Field 3:
Length = 5m (20m of fencing - 5m of width on each side)
Width = 5m
Area = 5m x 5m = 25m²
Therefore, Field 3 with a width of 5m will yield the most vegetables as it has the largest area of 25m².