Final answer:
To find the width of a rectangular dog pen with a known area and length, divide the area by the length. For an 18.9 square foot area with a length of 6.3 feet, the width is 3 feet.
Step-by-step explanation:
The student asked how to find the width of a rectangular dog pen with an area of 18.9 square feet and a length of 6.3 feet. To find the width, we must divide the area by the length, which gives us the width. So, we take 18.9 square feet and divide it by 6.3 feet.
Width = Area ÷ Length = 18.9 sq ft ÷ 6.3 ft = 3 feet.
Therefore, the width of the dog pen is 3 feet.