If the width is 6.5 then double that to work out the two widths which would be 13. Take that from the perimeter so you're left with 21. Half 21 to work out one length which is 10.5. Length = 10.5
The length of the rectangle is 10.5 units. This is calculated using the perimeter formula for rectangles and substituting the given values. By isolating the length, we arrive at the final measurement.
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