Answer: The length of the second longest side of quadrilateral EFGHJ is 7.71 feet.
Step-by-step explanation: Given that the quadrilateral ABCD is similar to quadrilateral EFGH.
The lengths of the three longest sides in quadrilateral ABCD are 20 feet, 18 feet, and 14 feet long and the two shortest sides of quadrilateral EFGH are 6 feet long and 5 feet long.
We are to find the length of the second longest side of quadrilateral EFGH.
Let x, y, z, w and x', y', z', w' represents the respective lengths of the quadrilaterals ABCD and EFGH is descending order.
Then, we have
x = 20 feet, y = 18 feet, z = 14 feet, z'=6 feet and w' = 5 feet.
We know that
the corresponding sides of two similar figures are proportional. so, for the given quadrilaterals, we have
Thus, the length of the second longest side of quadrilateral EFGHJ is 7.71 feet.