\[\boxed{\mathbf{1024\ (1024).\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[Пусть\ a,\ b - катеты,\ \]
\[c - гипотенуза,\ запишем\]
\[b = a + d,\ \ c = a + 2d = 4,\]
\[\ \ a² + b² = c²\ \ или\ \ \ a² + b² = 16.\]
\[Составим\ систему:\]
\[\left\{ \begin{matrix} a^{2} + b^{2} = 16 \\ a + 2d = 4\ \ \ \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ \ }\]
\[\left\{ \begin{matrix} a^{2} + (a + d)^{2} = 16 \\ 2d = 4 - a\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ \ \ \ }\]
\[\left\{ \begin{matrix} a^{2} + (a + d)^{2} = 16 \\ d = 2 - 0,5a\ \ \ \ \ \ \ \ \ \ \ \\ \end{matrix} \right.\ \]
\[a^{2} + (a + 2 - 0,5a)^{2} = 16\]
\[a^{2} + (0,5a + 2)^{2} = 16\]
\[a^{2} + 0,25a^{2} + 2a + 4 -\]
\[- 16 = 0\ \ \ \ | \cdot 4\]
\[5a^{2} + 8a - 48 = 0\]
\[a = \frac{- 8 + 32}{10} = 2,4\]
\[b = a + d = a + 2 - 0,5a =\]
\[= 2,4 + 2 - 1,2 = 3,2\]
\[Ответ:2,4\ см;3,2\ см.\]