\(S = 5,12\ м^{2};\ \ a = 3,2\ м:\)
\[b = S\ :a = 5,12\ :3,2 =\]
\[= 51,2\ :32 = 1,6\ м.\]
\[P = 2 \cdot (a + b) =\]
\[= 2 \cdot (3,2 + 1,6) = 2 \cdot 4,8 =\]
\[= 9,6\ м.\]
\[Ответ:9,6\ м.\]