Choose the correct option:

The internal radius of a cylindrical shaped iron pipe is 6 cm, and its length is 14 cm. If the thickness of the pipe is 2 cm, find the total surface area of the pipe.

Let r, w and h be the internal radius, thickness and height of a hollow cylindrical pipe respectively.

Given, the internal radius r = 6 cm, width = 2 cm, height = 14 cm
external radius of a hollow cylinder, R = w + r = 6 + 2 = 8 cm
r = 6 cm, R = 8 cm and h =14 cm.
Now, the total surface area of a cylindrical pipe = $\begin{array}{rcl} & & 2\mathrm{\pi }\left(R+r\right)\mathit{(}R\mathit{-}r\mathit{+}h\mathit{)}\end{array}$

$\begin{array}{rcl} & =& 2\times \frac{22}{7}\times \left(6+8\right)\left(8-6+14\right)\\ & =& 2\times 22\times 2\times 16\\ & =& 1408 {\mathrm{cm}}^2\end{array}$

Therefore, the total surface area of a cylindrical pipe = 1408 cm²