Ответ:
$$(11)^2 = 11 \cdot 11 = 121$$
$$(2,22)^2 = 2,22 \cdot 2,22 = 4,9284$$
$$(1\frac{6}{13})^2 = (\frac{13 + 6}{13})^2 = (\frac{19}{13})^2 = \frac{19^2}{13^2} = \frac{361}{169} = 2 \frac{23}{169} \approx 2,136$$