Answer:
1246 yards
Explanation:
To find the yard of fencing she needs for he cows, we simply need to find the perimeter of the rectangular area.
The area is 200 yards by 423 yards.
The perimeter is the sum of all the sides of a rectangle and it is given by:
P = 2(L + B)
P = 2(200 + 423) = 2(623)
P = 1246 yards.
She needs 1246 yards of fencing.