The total length of the fence is A. 84 m
Let the width of the garden be 6x meters and the length be 11x meters.
The total length of the fence is the perimeter of the rectangle minus the length of the side bounded by the river.
Perimeter = 2(width + length)
Total length of fence = Perimeter - 18
Substituting the expressions for width and length, we get:
Total length of fence = 2(6x + 11x) - 18
Total length of fence = 34x - 18
We need to find the values of x that satisfy the ratio 6:11.
This means that the width is 6/17 of the total length.
6x = 6/17 * (34x - 18)
Solving for x, we get:
x = 3
Substituting x back into the expression for the total length of the fence, we get:
Total length of fence = 34(3) - 18
Total length of fence = 102 - 18
Total length of fence = 84 meters