To evaluate \(-2.8 + (-53.65)\), you can add the two numbers together while considering their signs.
\[ -2.8 + (-53.65) = -2.8 - 53.65 \]
Now, perform the addition:
\[ -2.8 - 53.65 = -56.45 \]
Therefore, the answer is \(-56.45\).
So, the correct choice is:
\(-56.45\)