Here is the rewritten text in LaTeX code format:
```latex
\textbf{Example 13.12}
In triangle $ABC$, $b = 4.2 \text{ cm}$, $c = 7.5 \text{ cm}$, and $A = 48^\circ 36'$, solve the triangle completely. First, sketch the triangle using the given information.
Using the cosine rule: $48^\circ 36' = 48 + \frac{36}{60} = 48.6^\circ$
(Taking into account that $1^\circ = 60'$)
That is,
$a^2 = b^2 + c^2 - 2bc \cos A = 4.2^2 + 7.5^2 - 2 \times 4.2