Answer:
18 inches wide
Explanation:
Since the ratio of width to length is 3:7 we can assume that the length will be substancially longer than the width. The length is given as 42 inches long. To find how big the scale factor is, we divide 42 by 7 to get 6. 6 is our scale factor. take 3 x 6 =18 inches wide.
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