1. The problem is not fully clear, but it seems to involve a square area of 900 m² and some measurements: 1 m, 5 m, speeds of \(\sqrt{2}\) km/h and 10 km/h, and an angle \(\theta\). We will focus on the first question related to the 900 m² area. 2. Given the area of a square is \(A = s^2\), where \(s\) is the side length, we can find \(s\) by taking the square root of the area. 3. Calculate the side length: $$s = \sqrt{900} = 30\text{ m}$$ 4. This means each side of the square is 30 meters long. 5. If the question involves other parameters, please clarify, but for now, the first problem is solved by finding the side length of the square with area 900 m². Final answer: \(30\text{ m}\)