Try this option:
note, that distance between the parallel sides is shown via formula of area.
If it is possible, check the arithmetic.
Answer:
I got 1.75 too
Step-by-step explanation:
20/3.5 is 5.7
10/5.7 is 1.75
Formula for are of a rectangle:
A =L * W
1st isolate W
147 = 3W * W
147 = 3W^2
divide 147 by the by 3 on bot sides
29 = W^2
get ride of the square by square rooting on both sides
7 = W
2nd find the perimeter
P = 2(7) + 2(21)
P = 14 + 42
P = 56