Answer:
4.75 feet
Explanation:
Perimeter for any rectangular shape is given by 2(length + width).
Fencing the garden means one wiring the garden along the perimeter.
Thus, it can be concluded that garden has perimeter of 26 feet as given in question.
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Let the width be x feet
given that, He wants the length of the garden to be 3 1/2 feet longer than the width
thus, length of garden = x + 3 1/2 feet = x + 3.5 feet
if length is x+3.5 feet and width is x feet.
Then perimeter = 2( x+3.5 + x) = 2(2x+3.5) = (4x + 7) feet.
This perimeter will be equal to 26 feet fence
thus,
(4x + 7) = 26
=> 4x = 26 - 7 = 19
=> x = 19/4 = 4.75 feet
x is width of garden.
Thus, he should make the garden 4.75 feet wide.