Step-by-step answer:
This is a regular heptagon, means it has 7 <em>congruent</em> sides and 7 <em>congruent </em>vertex angles.
To work with polygons, there is a very important piece of information that you must know to solve the majority of related problems.
This is:
sum of exterior angles of polygons = 360 degrees.
If you don't remember the 360 degrees, think of the sum of exterior angles of an equilateral triangle, which is 3*(180-60)=3*120=360! It works!
For a regular heptagon, c = 360/7=51.43 degrees approx.
This means that each vertex angle measures
vertex angle = 180-c
So since 2d+the vertex angle = 360, we have
2d+(180-c)=360
solve for d:
2d=360-(180-c)=180+c
d=(180+c)/2=90+c/2=115.71 degrees. (approx.)
Let's use the variable x to represent the length of the first and second pieces.
If the third piece has twice the length of the first and second, its length is 2x.
If the fourth piece has half the length of the first and second, its length is 0.5*x.
Adding all four pieces and equating to 54 inches, we have:

So the length of each piece is:
12 inches, 12 inches, 24 inches and 6 inches.
Im not shore but i think it is 38?<span />