Answers:
Equation is 2*(2*W+W) = 102
Width is 17
Length is 34
=============================
Explanation:
L = 2*W because the length is twice the width
2*(L+W) = P is the perimeter formula
Replace P with the given perimeter (102). Also replace L with 2*W. Then isolate W
2*(L+W) = P
2*(2*W+W) = 102
2*(3W) = 102
6W = 102
6W/6 = 102/6
W = 17
If the width is W = 17, then the length is
L = 2*W = 2*17 = 34
So the width and length of this rectangle is 17 by 34
---------
Check:
P = 2*(L+W)
P = 2*(34+17)
P = 2*51
P = 102
Answer is confirmed