Parallel packing squares into a rhombus

Suppose that \(R_{\alpha}\) $R_{\alpha }$ is a rhombus with side length \(1\) $1$ and with acute angle \(\alpha\) $\alpha$ . Let \(\{S_{n}\}\) $\{S_n\}$ be any collection of squares. In this note a tight upper bound of the sum of the areas of squares from \(\{S_{n}\}\) $\{S_n\}$ that can be parallel packed into \(R_{\alpha}\) $R_{\alpha }$ is given.