如下图所示，从一个长方形中剪掉了一个半圆。剪掉前，该长方形的周长是 56 cm。阴影图形的周长是多少？（取 $\pi = \frac{22}{7}$）

1. Find the length of the rectangle using its perimeter.

Let the length of the rectangle be $L$.
Perimeter $= 2L + 2W = 56$
$2L + 2(8) = 56$
$2L + 16 = 56$
$2L = 40$
$L = 20$ cm

2. Calculate the arc length of the semicircle.

Diameter of semicircle $d = 14$ cm.
Arc length $= \frac{1}{2} \times \pi d = \frac{1}{2} \times \frac{22}{7} \times 14 = 22$ cm

3. Calculate the perimeter of the shaded figure.

The perimeter of the shaded figure consists of the top length, the two side widths, the two straight segments on the bottom edge, and the arc of the semicircle.
The two straight segments on the bottom edge sum to $L - 14 = 20 - 14 = 6$ cm.
Perimeter $= L + 2W + (L - 14) + \text{Arc length}$
Perimeter $= 20 + 2(8) + 6 + 22 = 20 + 16 + 6 + 22 = 64$ cm