Given:
The figure of a wallpaper border.
To find:
The total required border.
Solution:
The given figure has 8 vertices and 8 edges (sides).
From the given figure it is clear that the length ( in feet) of 8 edges of the figure are 12, 2, 2, 2, 2, 3, 12, 7.
We need to find the total required border. So, we have to find the perimeter of the figure.
Add the lengths of all edges to get the perimeter of the given figure.
So, Chloe should buy 42 feet of border.
Therefore, the correct option is B.