The diagram shown consists of circles with radius $1 \mathrm{~cm}$ and semi-circles with radius $1 \mathrm{~cm}$. The total shaded area, in $\mathrm{cm}^{2}$, is
(A) $10 \pi$
(B) $9.5 \pi$
(C) $9 \pi$
(D) $8.5 \pi$
(E) $8 \pi$

![](https://cdn.mathpix.com/cropped/2024_04_20_6027bc27089ed4fc493cg-041.jpg?height=236&width=293&top_left_y=717&top_left_x=1377)
The shaded area in the top three rows of the diagram contains 6 circles with radius $1 \mathrm{~cm}$.

The shaded area in the bottom row of the diagram contains 4 semi-circles with radius $1 \mathrm{~cm}$, whose combined area is equal to the area of 2 circles with radius $1 \mathrm{~cm}$.

In total, the shaded area of the diagram contains $6+2=8$ circles with radius $1 \mathrm{~cm}$. In $\mathrm{cm}^{2}$, the total shaded area is $8 \times \pi \times 1^{2}=8 \pi$.

ANSWER: (E)