Final answer:
The area of the rectangular field is 300 square meters and the perimeter is 70 meters.
Step-by-step explanation:
To find the area of the rectangular field, we need to multiply the length and width. The length of the field is given as 20 meters and the ratio of length to width is 4:3. Using this ratio, we can determine that the width is (3/4) * 20 = 15 meters. So, the area of the field is 20 * 15 = 300 square meters.
To find the perimeter, we need to add up all the sides of the rectangle. The length is 20 meters and the width is 15 meters. So, the perimeter is 2 * (20 + 15) = 2 * 35 = 70 meters.